diff --git a/src/components/settings/EmailChangeDialog.tsx b/src/components/settings/EmailChangeDialog.tsx
index 9283629f..d36b01ef 100644
--- a/src/components/settings/EmailChangeDialog.tsx
+++ b/src/components/settings/EmailChangeDialog.tsx
@@ -253,7 +253,7 @@ export function EmailChangeDialog({ open, onOpenChange, currentEmail, userId }:
             metadata: { 
               currentEmail, 
               newEmail: data.newEmail,
-              errorType: error.constructor.name 
+              errorType: error instanceof Error ? error.constructor.name : 'Unknown'
             } 
           }
         );
diff --git a/src/components/ui/sidebar.tsx b/src/components/ui/sidebar.tsx
index 37ea9ff6..dd067989 100644
--- a/src/components/ui/sidebar.tsx
+++ b/src/components/ui/sidebar.tsx
@@ -78,7 +78,7 @@ const SidebarProvider = React.forwardRef<
       state,
       open,
       setOpen,
-      isMobile,
+      isMobile: isMobile ?? false,
       openMobile,
       setOpenMobile,
       toggleSidebar,
diff --git a/src/components/upload/EntityMultiImageUploader.tsx b/src/components/upload/EntityMultiImageUploader.tsx
index ceee256e..497fd939 100644
--- a/src/components/upload/EntityMultiImageUploader.tsx
+++ b/src/components/upload/EntityMultiImageUploader.tsx
@@ -86,7 +86,7 @@ export function EntityMultiImageUploader({
         .from('photos')
         .select('id, cloudflare_image_url, cloudflare_image_id, caption, title')
         .eq('entity_type', entityType)
-        .eq('entity_id', entityId)
+        .eq('entity_id', entityId || '')
         .order('created_at', { ascending: false });
 
       if (error) throw error;
@@ -314,7 +314,7 @@ export function EntityMultiImageUploader({
     
     const existingCount = value.uploaded.filter(img => !img.isLocal).length;
     const newCount = value.uploaded.filter(img => img.isLocal).length;
-    const parts = [];
+    const parts: string[] = [];
     
     if (mode === 'edit' && existingCount > 0) {
       parts.push(`${existingCount} existing photo${existingCount !== 1 ? 's' : ''}`);
diff --git a/src/components/upload/EntityPhotoGallery.tsx b/src/components/upload/EntityPhotoGallery.tsx
index ac775991..c6ff02e3 100644
--- a/src/components/upload/EntityPhotoGallery.tsx
+++ b/src/components/upload/EntityPhotoGallery.tsx
@@ -68,7 +68,7 @@ export function EntityPhotoGallery({
         url: photo.cloudflare_image_url,
         caption: photo.caption || undefined,
         title: photo.title || undefined,
-        user_id: photo.submitted_by,
+        user_id: photo.submitted_by || '',
         created_at: photo.created_at,
       })) || [];
 
@@ -148,7 +148,7 @@ export function EntityPhotoGallery({
             </p>
           </div>
           <div className="flex flex-col sm:flex-row gap-2 w-full sm:w-auto">
-            {isModerator && photos.length > 0 && (
+            {isModerator() && photos.length > 0 && (
               <Button onClick={() => setShowManagement(true)} variant="outline" className="gap-2 w-full sm:w-auto">
                 <Settings className="w-4 h-4" />
                 <span className="sm:inline">Manage</span>
diff --git a/src/components/upload/PhotoManagementDialog.tsx b/src/components/upload/PhotoManagementDialog.tsx
index 7b3d38a2..1c9cced5 100644
--- a/src/components/upload/PhotoManagementDialog.tsx
+++ b/src/components/upload/PhotoManagementDialog.tsx
@@ -78,7 +78,11 @@ export function PhotoManagementDialog({
         .order('order_index', { ascending: true });
 
       if (error) throw error;
-      setPhotos(data || []);
+      setPhotos((data || []).map(p => ({
+        ...p,
+        order_index: p.order_index ?? 0,
+        is_featured: p.is_featured ?? false
+      })) as Photo[]);
     } catch (error: unknown) {
       toast({
         title: 'Error',
diff --git a/src/components/upload/UppyPhotoSubmissionUpload.tsx b/src/components/upload/UppyPhotoSubmissionUpload.tsx
index 21e778fa..86afb4cf 100644
--- a/src/components/upload/UppyPhotoSubmissionUpload.tsx
+++ b/src/components/upload/UppyPhotoSubmissionUpload.tsx
@@ -110,6 +110,9 @@ export function UppyPhotoSubmissionUpload({
             const { uploadURL, id: cloudflareId } = uploadData;
 
             // Upload file to Cloudflare
+            if (!photo.file) {
+              throw new Error('Photo file is missing');
+            }
             const formData = new FormData();
             formData.append('file', photo.file);
 
diff --git a/src/hooks/moderation/useEntityCache.ts b/src/hooks/moderation/useEntityCache.ts
index e95da361..865b27b1 100644
--- a/src/hooks/moderation/useEntityCache.ts
+++ b/src/hooks/moderation/useEntityCache.ts
@@ -133,7 +133,7 @@ export function useEntityCache() {
     const uncachedIds = getUncachedIds(type, ids);
     if (uncachedIds.length === 0) {
       // All entities are cached, return them
-      return ids.map(id => getCached(type, id)).filter(Boolean);
+      return ids.map(id => getCached(type, id)).filter((item): item is EntityTypeMap[T] => item !== undefined);
     }
 
     try {
diff --git a/src/hooks/moderation/useModerationActions.ts b/src/hooks/moderation/useModerationActions.ts
index ebaa2cf0..c0ba22e4 100644
--- a/src/hooks/moderation/useModerationActions.ts
+++ b/src/hooks/moderation/useModerationActions.ts
@@ -316,10 +316,12 @@ export function useModerationActions(config: ModerationActionsConfig): Moderatio
       });
     },
     onSuccess: (data) => {
-      toast({
-        title: `Content ${data.action}`,
-        description: `The ${data.item.type} has been ${data.action}`,
-      });
+      if (data) {
+        toast({
+          title: `Content ${data.action}`,
+          description: `The ${data.item.type} has been ${data.action}`,
+        });
+      }
     },
     onSettled: () => {
       // Always refetch to ensure consistency
diff --git a/src/hooks/moderation/useProfileCache.ts b/src/hooks/moderation/useProfileCache.ts
index 1ed9af12..3bb27837 100644
--- a/src/hooks/moderation/useProfileCache.ts
+++ b/src/hooks/moderation/useProfileCache.ts
@@ -113,12 +113,21 @@ export function useProfileCache() {
 
       // Cache the fetched profiles
       if (data) {
-        data.forEach((profile: CachedProfile) => {
-          setCached(profile.user_id, profile);
+        data.forEach((profile) => {
+          const cachedProfile: CachedProfile = {
+            ...profile,
+            display_name: profile.display_name || undefined,
+            avatar_url: profile.avatar_url || undefined
+          };
+          setCached(profile.user_id, cachedProfile);
         });
       }
 
-      return data || [];
+      return (data || []).map(profile => ({
+        ...profile,
+        display_name: profile.display_name || undefined,
+        avatar_url: profile.avatar_url || undefined
+      }));
     } catch (error: unknown) {
       logger.error('Failed to bulk fetch profiles:', { error: getErrorMessage(error) });
       return [];
diff --git a/src/hooks/useAutocompleteData.ts b/src/hooks/useAutocompleteData.ts
index 5ac0adad..f0d2293c 100644
--- a/src/hooks/useAutocompleteData.ts
+++ b/src/hooks/useAutocompleteData.ts
@@ -64,13 +64,13 @@ export function useStatesProvinces(country?: string) {
         const { data, error } = await supabase
           .from('locations')
           .select('state_province')
-          .eq('country', country)
+          .eq('country', country || '')
           .not('state_province', 'is', null);
 
         if (error) throw error;
 
         const uniqueStates = Array.from(
-          new Set(data?.map(item => item.state_province) || [])
+          new Set(data?.map(item => item.state_province).filter((s): s is string => s != null) || [])
         ).sort();
 
         setStatesProvinces(
@@ -153,7 +153,7 @@ export function useRideModels(manufacturerId?: string) {
         const { data, error } = await supabase
           .from('ride_models')
           .select('id, name')
-          .eq('manufacturer_id', manufacturerId)
+          .eq('manufacturer_id', manufacturerId || '')
           .order('name');
 
         if (error) throw error;
@@ -198,7 +198,7 @@ export function useCompanyHeadquarters() {
         if (error) throw error;
 
         const uniqueHeadquarters = Array.from(
-          new Set(data?.map(item => item.headquarters_location) || [])
+          new Set(data?.map(item => item.headquarters_location).filter((hq): hq is string => hq != null) || [])
         ).sort();
 
         setHeadquarters(
diff --git a/src/hooks/useProfile.tsx b/src/hooks/useProfile.tsx
index 76cb37cc..c2de7049 100644
--- a/src/hooks/useProfile.tsx
+++ b/src/hooks/useProfile.tsx
@@ -18,7 +18,7 @@ export function useProfile(userId: string | undefined) {
       // Use get_filtered_profile RPC for privacy-aware field filtering
       const { data, error } = await supabase.rpc('get_filtered_profile', {
         _profile_user_id: userId,
-        _viewer_id: viewerId
+        _viewer_id: viewerId || ''
       });
       
       if (error) {
diff --git a/src/hooks/useSearch.tsx b/src/hooks/useSearch.tsx
index 9bb629ba..2b0844d0 100644
--- a/src/hooks/useSearch.tsx
+++ b/src/hooks/useSearch.tsx
@@ -99,8 +99,8 @@ export function useSearch(options: UseSearchOptions = {}) {
             type: 'park',
             title: park.name,
             subtitle: [park.location?.city, park.location?.state_province, park.location?.country].filter(Boolean).join(', '),
-            image: park.banner_image_url || park.card_image_url,
-            rating: park.average_rating,
+            image: park.banner_image_url || park.card_image_url || undefined,
+            rating: park.average_rating ?? undefined,
             slug: park.slug,
             data: park
           });
@@ -125,8 +125,8 @@ export function useSearch(options: UseSearchOptions = {}) {
             type: 'ride',
             title: ride.name,
             subtitle: `at ${ride.park?.name || 'Unknown Park'}`,
-            image: ride.image_url,
-            rating: ride.average_rating,
+            image: ride.image_url || undefined,
+            rating: ride.average_rating ?? undefined,
             slug: ride.slug,
             data: ride
           });
@@ -147,7 +147,7 @@ export function useSearch(options: UseSearchOptions = {}) {
             type: 'company',
             title: company.name,
             subtitle: company.company_type?.replace('_', ' ').replace(/\b\w/g, l => l.toUpperCase()) || 'Company',
-            image: company.logo_url,
+            image: company.logo_url || undefined,
             slug: company.slug,
             data: company
           });
diff --git a/src/hooks/useVersionComparison.ts b/src/hooks/useVersionComparison.ts
index 8509b055..1cdf77ca 100644
--- a/src/hooks/useVersionComparison.ts
+++ b/src/hooks/useVersionComparison.ts
@@ -29,8 +29,8 @@ export function useVersionComparison(
         // Use the database function to get diff
         const { data, error: rpcError } = await supabase.rpc('get_version_diff', {
           p_entity_type: entityType,
-          p_from_version_id: fromVersionId,
-          p_to_version_id: toVersionId
+          p_from_version_id: fromVersionId || '',
+          p_to_version_id: toVersionId || ''
         });
 
         if (rpcError) throw rpcError;
diff --git a/src/lib/entitySubmissionHelpers.ts b/src/lib/entitySubmissionHelpers.ts
index 89203759..026a6ddb 100644
--- a/src/lib/entitySubmissionHelpers.ts
+++ b/src/lib/entitySubmissionHelpers.ts
@@ -564,11 +564,11 @@ export async function submitParkUpdate(
       submission_id: submissionData.id,
       item_type: 'park',
       action_type: 'edit',
-      item_data: {
+      item_data: JSON.parse(JSON.stringify({
         ...extractChangedFields(data, existingPark),
         park_id: parkId,  // Always include for relational integrity
-        images: processedImages as unknown as Json
-      },
+        images: processedImages
+      })) as Json,
       original_data: JSON.parse(JSON.stringify(existingPark)),
       status: 'pending' as const,
       order_index: 0