I really like this display...a lot!
My one thought, is if you could basically make everyone removable, so you'd have luke and the scout trooper on their speederbikes for a couple months, and then swap it out with Luke deflecting blaster shots. It would streamline the diorama design a bit. That way you're not trying to shoehorn two different action scenes in the same diorama, which takes away slightly from how cool the diorama is.