Hi Mike, I think this is a great idea! Your idea of making different bits available got me thinking. You could make the base and walls generic enough that you could then sell different add-on kits to make them more specific to the modellers diorama/display needs. For example: Add on parts to turn the base into a repair bay for aircraft, a repair bay for destroids, a hangar for destroids, a hangar for aircraft, add on parts that would be specific to space based hangars and ones for land based, etc...
I'd love to have a hanger that is made to house destroids, the pilots have to take stairs/elevators up and walk out on elevated platforms to climb into the destroid cockpits etc... We'd definately need people for this as well.
I don't think there's anything wrong with taking some design cues from the old 1/100 factory design either. I really liked the spotlights they had mounted on the floor shining up on the mecha. I really liked the big moveable gantry that was in the kit as well.