A lot of good ideas, RL! I second the notion of using the Ewoks with Blasters footage if possible.

Rewatching the feast preparation scene, I suddenly realized why it doesn’t feel threatening: the music. Almost the entire scene has a tribal beat which gives a clear ‘happy festivities’ vibe. The only moment that feels in any way dramatic is when 3PO starts levitating, which also happens to be when the tribal music stops.

My solution would be to remove the tribal music from the scene. It would probably be tricky since there’s so many other sounds, but I am willing to bet that if that scene had only dialogue and sound effects, it would be 200% more creepy.