diff --git a/src/app/page.tsx b/src/app/page.tsx
index ca3a1329..6e2aff08 100644
--- a/src/app/page.tsx
+++ b/src/app/page.tsx
@@ -36,9 +36,9 @@ export default function Home() {
 
   // Client-side only FTUX check (SSR-safe)
   useEffect(() => {
-    // TODO: REVERT BEFORE PRODUCTION - Testing override to always show FTUX
-    setShowFTUX(true);
-    // Production code: if (!getFTUXCompleted()) { setShowFTUX(true); }
+    if (!getFTUXCompleted()) {
+      setShowFTUX(true);
+    }
   }, []);
 
   const handleFTUXComplete = () => {
diff --git a/src/components/FloatingActionBar.tsx b/src/components/FloatingActionBar.tsx
index 1cc5457a..f270caee 100644
--- a/src/components/FloatingActionBar.tsx
+++ b/src/components/FloatingActionBar.tsx
@@ -457,7 +457,7 @@ export function FloatingActionBar() {
       // Normal execution
       executeWorkflow();
     }
-  }, [isRunning, stopWorkflow, executeWorkflow]);
+  }, [isRunning, stopWorkflow, executeWorkflow, mockTutorialExecution]);
 
   const handleRunFromSelected = () => {
     if (selectedNode) {
diff --git a/src/components/Header.tsx b/src/components/Header.tsx
index 797140cd..ab6c6190 100644
--- a/src/components/Header.tsx
+++ b/src/components/Header.tsx
@@ -312,6 +312,7 @@ export function Header() {
                     onClick={handleNewProject}
                     className="relative p-1.5 text-neutral-400 hover:text-neutral-200 hover:bg-neutral-800 rounded transition-colors"
                     title="Save project"
+                    data-tutorial="save-button"
                   >
                     <svg
                       className="w-4 h-4"
diff --git a/src/components/WorkflowCanvas.tsx b/src/components/WorkflowCanvas.tsx
index 35e840b5..9c5513aa 100644
--- a/src/components/WorkflowCanvas.tsx
+++ b/src/components/WorkflowCanvas.tsx
@@ -316,7 +316,7 @@ export function WorkflowCanvas() {
   const clearWorkflow = useWorkflowStore((state) => state.clearWorkflow);
   const setHoveredNodeId = useWorkflowStore((state) => state.setHoveredNodeId);
   const openAnnotationModal = useAnnotationStore((state) => state.openModal);
-  const { screenToFlowPosition, getViewport, zoomIn, zoomOut, setViewport, setCenter, fitView } = useReactFlow();
+  const { screenToFlowPosition, getViewport, zoomIn, zoomOut, setViewport, setCenter } = useReactFlow();
   const { show: showToast } = useToast();
   const [isDragOver, setIsDragOver] = useState(false);
   const [dropType, setDropType] = useState<"image" | "audio" | "workflow" | "node" | null>(null);
@@ -2488,7 +2488,7 @@ export function WorkflowCanvas() {
           initialCapabilityFilter={fallbackDialogState.capability}
           showClearOption
           onClearSelection={() => {
-            updateNodeData(fallbackDialogState.nodeId, { fallbackModel: undefined });
+            updateNodeData(fallbackDialogState.nodeId, { fallbackModel: undefined, fallbackParameters: undefined });
             setFallbackDialogState(null);
           }}
           onModelSelected={(model) => {
diff --git a/src/components/nodes/BaseNode.tsx b/src/components/nodes/BaseNode.tsx
index b1bc3dbe..dcdcf141 100644
--- a/src/components/nodes/BaseNode.tsx
+++ b/src/components/nodes/BaseNode.tsx
@@ -293,7 +293,7 @@ export function BaseNode({
         ? `relative flex flex-col w-full h-full overflow-visible bg-neutral-800 rounded-lg ${selected ? "ring-2 ring-blue-500/40 shadow-lg shadow-blue-500/25" : ""}`
         : "contents"}
       onDoubleClick={handleResizeHandleDblClick}
-      data-tutorial={dataTutorial}
+      data-tutorial={hasExpandedSettings ? dataTutorial : undefined}
     >
       <NodeResizer
         isVisible={selected}
@@ -316,6 +316,7 @@ export function BaseNode({
           ${!fullBleed && selected && settingsExpanded ? "border-blue-500" : ""}
           ${className}
         `}
+        data-tutorial={!hasExpandedSettings ? dataTutorial : undefined}
         onMouseEnter={(e) => {
           if (e.buttons !== 0 || isPanningRef.current || isDraggingNodeRef.current) return;
           setHoveredNodeId(id);
diff --git a/src/components/nodes/GenerateImageNode.tsx b/src/components/nodes/GenerateImageNode.tsx
index cf19d1d6..8d021b25 100644
--- a/src/components/nodes/GenerateImageNode.tsx
+++ b/src/components/nodes/GenerateImageNode.tsx
@@ -68,6 +68,12 @@ export function GenerateImageNode({ id, data, selected }: NodeProps<NanoBananaNo
   const [isBrowseDialogOpen, setIsBrowseDialogOpen] = useState(false);
   const [settingsTab, setSettingsTab] = useState<"primary" | "fallback">("primary");
 
+  useEffect(() => {
+    if (!nodeData.fallbackModel && settingsTab === "fallback") {
+      setSettingsTab("primary");
+    }
+  }, [nodeData.fallbackModel, settingsTab]);
+
   // Inline parameters infrastructure
   const { inlineParametersEnabled } = useInlineParameters();
 
diff --git a/src/components/nodes/GenerateVideoNode.tsx b/src/components/nodes/GenerateVideoNode.tsx
index 9dbf4944..03165235 100644
--- a/src/components/nodes/GenerateVideoNode.tsx
+++ b/src/components/nodes/GenerateVideoNode.tsx
@@ -56,6 +56,13 @@ export function GenerateVideoNode({ id, data, selected }: NodeProps<GenerateVide
   const [isBrowseDialogOpen, setIsBrowseDialogOpen] = useState(false);
   const [isLoadingCarouselVideo, setIsLoadingCarouselVideo] = useState(false);
   const [settingsTab, setSettingsTab] = useState<"primary" | "fallback">("primary");
+
+  useEffect(() => {
+    if (!nodeData.fallbackModel && settingsTab === "fallback") {
+      setSettingsTab("primary");
+    }
+  }, [nodeData.fallbackModel, settingsTab]);
+
   const videoBlobUrl = useVideoBlobUrl(nodeData.outputVideo ?? null);
   const videoAutoplayRef = useVideoAutoplay(id, selected);
 
diff --git a/src/components/nodes/LLMFallbackPopover.tsx b/src/components/nodes/LLMFallbackPopover.tsx
index 3db7c3fb..66cb1bbf 100644
--- a/src/components/nodes/LLMFallbackPopover.tsx
+++ b/src/components/nodes/LLMFallbackPopover.tsx
@@ -88,7 +88,7 @@ export function LLMFallbackPopover({ nodeId, onClose }: LLMFallbackPopoverProps)
   };
 
   const handleRemove = () => {
-    updateNodeData(nodeId, { fallbackModel: undefined });
+    updateNodeData(nodeId, { fallbackModel: undefined, fallbackParameters: undefined });
     onClose();
   };
 
diff --git a/src/components/nodes/LLMGenerateNode.tsx b/src/components/nodes/LLMGenerateNode.tsx
index e22e2979..411ec6f5 100644
--- a/src/components/nodes/LLMGenerateNode.tsx
+++ b/src/components/nodes/LLMGenerateNode.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import { useCallback, useState } from "react";
+import { useCallback, useEffect, useState } from "react";
 import { Handle, Position, NodeProps, Node } from "@xyflow/react";
 import { BaseNode } from "./BaseNode";
 import { useWorkflowStore } from "@/store/workflowStore";
@@ -57,6 +57,12 @@ export function LLMGenerateNode({ id, data, selected }: NodeProps<LLMGenerateNod
   const [copied, setCopied] = useState(false);
   const [settingsTab, setSettingsTab] = useState<"primary" | "fallback">("primary");
 
+  useEffect(() => {
+    if (!nodeData.fallbackModel && settingsTab === "fallback") {
+      setSettingsTab("primary");
+    }
+  }, [nodeData.fallbackModel, settingsTab]);
+
   const handleCopyOutput = useCallback(async () => {
     if (nodeData.outputText) {
       try {
diff --git a/src/components/nodes/OutputGalleryNode.tsx b/src/components/nodes/OutputGalleryNode.tsx
index b6f73101..4c97c3fb 100644
--- a/src/components/nodes/OutputGalleryNode.tsx
+++ b/src/components/nodes/OutputGalleryNode.tsx
@@ -82,19 +82,24 @@ export function OutputGalleryNode({ id, data, selected }: NodeProps<OutputGaller
     if (!item) return;
 
     if (item.type === "image") {
-      const filtered = (nodeData.images || []).filter((img) => img !== item.src);
-      updateNodeData(id, { images: filtered });
+      const images = [...(nodeData.images || [])];
+      const imgIndex = images.indexOf(item.src);
+      if (imgIndex !== -1) images.splice(imgIndex, 1);
+      updateNodeData(id, { images });
     } else {
-      const filtered = (nodeData.videos || []).filter((vid) => vid !== item.src);
-      updateNodeData(id, { videos: filtered });
+      const videos = [...(nodeData.videos || [])];
+      const vidIndex = videos.indexOf(item.src);
+      if (vidIndex !== -1) videos.splice(vidIndex, 1);
+      updateNodeData(id, { videos });
     }
 
     // Adjust lightbox after removal
     if (lightboxIndex !== null) {
-      if (displayMedia.length <= 1) {
+      const newLength = displayMedia.length - 1;
+      if (newLength <= 0) {
         setLightboxIndex(null);
-      } else if (lightboxIndex >= displayMedia.length - 1) {
-        setLightboxIndex(displayMedia.length - 2);
+      } else if (lightboxIndex >= newLength) {
+        setLightboxIndex(newLength - 1);
       }
     }
   }, [displayMedia, nodeData.images, nodeData.videos, updateNodeData, id, lightboxIndex]);
diff --git a/src/components/onboarding/FTUXApiKeysStep.tsx b/src/components/onboarding/FTUXApiKeysStep.tsx
index 14d01de9..ace8d11c 100644
--- a/src/components/onboarding/FTUXApiKeysStep.tsx
+++ b/src/components/onboarding/FTUXApiKeysStep.tsx
@@ -75,6 +75,7 @@ const providers: ProviderInfo[] = [
 
 export function FTUXApiKeysStep({}: FTUXStepProps) {
   const updateProviderApiKey = useWorkflowStore((state) => state.updateProviderApiKey);
+  const providerSettings = useWorkflowStore((state) => state.providerSettings);
   const [envStatus, setEnvStatus] = useState<EnvStatusResponse | null>(null);
   const [showKey, setShowKey] = useState<Record<ProviderType, boolean>>({
     gemini: false,
@@ -85,14 +86,21 @@ export function FTUXApiKeysStep({}: FTUXStepProps) {
     kie: false,
     wavespeed: false,
   });
-  const [localKeys, setLocalKeys] = useState<Record<ProviderType, string>>({
-    gemini: "",
-    openai: "",
-    anthropic: "",
-    replicate: "",
-    fal: "",
-    kie: "",
-    wavespeed: "",
+  const [localKeys, setLocalKeys] = useState<Record<ProviderType, string>>(() => {
+    const keys: Record<ProviderType, string> = {
+      gemini: "",
+      openai: "",
+      anthropic: "",
+      replicate: "",
+      fal: "",
+      kie: "",
+      wavespeed: "",
+    };
+    for (const id of Object.keys(keys) as ProviderType[]) {
+      const saved = providerSettings.providers[id]?.apiKey;
+      if (saved) keys[id] = saved;
+    }
+    return keys;
   });
 
   useEffect(() => {
diff --git a/src/store/execution/generate3dExecutor.ts b/src/store/execution/generate3dExecutor.ts
index 6ac9322c..468980de 100644
--- a/src/store/execution/generate3dExecutor.ts
+++ b/src/store/execution/generate3dExecutor.ts
@@ -184,6 +184,11 @@ export async function executeGenerate3D(
     displayName: "",
   };
 
+  if (!primaryModel.modelId) {
+    updateNodeData(node.id, { status: "error", error: "No model selected" });
+    throw new Error("No model selected");
+  }
+
   await runWithFallback({
     nodeId: node.id,
     primary: primaryModel,
@@ -191,6 +196,6 @@ export async function executeGenerate3D(
     fallbackParameters: nodeData.fallbackParameters,
     updateNodeData,
     runOnce,
-    clearOutput: { outputVideo: null },
+    clearOutput: { output3dUrl: null },
   });
 }
diff --git a/src/store/ftuxStore.ts b/src/store/ftuxStore.ts
index 2b450dae..982b28ac 100644
--- a/src/store/ftuxStore.ts
+++ b/src/store/ftuxStore.ts
@@ -212,7 +212,6 @@ const initialTutorialSteps: TutorialStep[] = [
     waitForClick: true,
     links: [
       { text: "Join our Discord community", url: "https://discord.gg/node-banana" },
-      { text: "View documentation", url: "https://docs.nodebanana.com" },
     ],
     completed: false,
   },
@@ -240,15 +239,25 @@ export const useFTUXStore = create<FTUXState>((set, get) => ({
   loadTutorialSampleImage: async () => {
     try {
       const response = await fetch("/sample-images/owl.jpg");
+      if (!response.ok) {
+        console.error("Failed to load tutorial sample image: HTTP", response.status);
+        set({ tutorialSampleImage: null });
+        return;
+      }
       const blob = await response.blob();
       const reader = new FileReader();
       reader.onloadend = () => {
         const base64 = reader.result as string;
         set({ tutorialSampleImage: base64 });
       };
+      reader.onerror = () => {
+        console.error("Failed to read tutorial sample image as data URL");
+        set({ tutorialSampleImage: null });
+      };
       reader.readAsDataURL(blob);
     } catch (error) {
       console.error("Failed to load tutorial sample image:", error);
+      set({ tutorialSampleImage: null });
     }
   },
 
diff --git a/src/store/workflowStore.ts b/src/store/workflowStore.ts
index 5ee65ca6..9f95e051 100644
--- a/src/store/workflowStore.ts
+++ b/src/store/workflowStore.ts
@@ -1534,9 +1534,16 @@ const workflowStoreImpl: StateCreator<WorkflowStore> = (set, get) => ({
           }
         }
 
+        // Remap startLevel to prefixLevels index (original index may not match after partitioning)
+        let prefixStartLevel = 0;
+        if (startFromNodeId) {
+          const idx = prefixLevels.findIndex((l) => l.nodeIds.includes(startFromNodeId));
+          prefixStartLevel = idx !== -1 ? idx : 0;
+        }
+
         // Execute prefix once
         logger.info('node.execution', 'Executing prefix levels', { count: prefixLevels.length });
-        await executeLevels(prefixLevels, startLevel);
+        await executeLevels(prefixLevels, prefixStartLevel);
 
         // Execute loop N times
         const loopCount = loopEdge.data?.loopCount ?? 3;
diff --git a/src/types/nodes.ts b/src/types/nodes.ts
index 901dafae..5feb68fd 100644
--- a/src/types/nodes.ts
+++ b/src/types/nodes.ts
@@ -334,7 +334,7 @@ export interface OutputNodeData extends BaseNodeData {
 export interface OutputGalleryNodeData extends BaseNodeData {
   images: string[]; // Array of base64 data URLs from connected nodes
   imageRefs?: string[]; // External storage refs for images
-  videos: string[]; // Array of video URLs from connected nodes
+  videos?: string[]; // Array of video URLs from connected nodes
   videoRefs?: string[]; // External storage refs for videos
 }
 
diff --git a/src/utils/mediaStorage.ts b/src/utils/mediaStorage.ts
index 27909e46..e8884712 100644
--- a/src/utils/mediaStorage.ts
+++ b/src/utils/mediaStorage.ts
@@ -455,7 +455,7 @@ async function externalizeNodeMedia(
 
       // Externalize gallery videos
       for (let i = 0; i < (d.videos?.length || 0); i++) {
-        const vid = d.videos[i];
+        const vid = d.videos![i];
         const existingRef = galleryVideoRefs[i];
         if (existingRef && isDataUrl(vid)) {
           // Already has ref, just keep it
@@ -1084,9 +1084,9 @@ async function hydrateNodeMedia(
       newData = {
         ...d,
         images: filteredImages,
-        imageRefs: filteredImageRefs.some(r => r !== "") ? filteredImageRefs : d.imageRefs,
+        imageRefs: filteredImageRefs,
         videos: filteredVideos,
-        videoRefs: filteredVideoRefs.some(r => r !== "") ? filteredVideoRefs : d.videoRefs,
+        videoRefs: filteredVideoRefs,
       };
       break;
     }