1) - Name of city... good question. Here's a few ideas -
2) - Native race... I think we were going for more of a "melting pot" of species, but perhaps a dominant race could be Arcona. Going with the 4 arm race of aliens at this point I think is too late in the game...
3) - Security Force - I thought that Fritz had a few that worked out ok? Fritz?
4) - For characters, I could provide a Rykrof Enloe and a Freelo or something to be mixed in with the Rebels, perhaps on a rebel land speeder or something, if you guys like that idea.
5) - Yes Vader, I think is essential to this diorama. I could provide a Vader and possibly a commander at his side too. For Rebel leaders, I think we should stay away from established folks like Luke/Han/Leia/etc.