Hmm... That does seem quite fitting. But which characters should be PCs? R2-D2 is an easy one, as Pete already plays him and he'd be returning. I'm not sure that Sally would return to playing C3PO or that she would play any of the characters I can think of. Jim playing Leia would be pretty hilarious, though he could also play Han and be in-character. I feel like Obi-Wan will be an NPC and they'll later find out that he's supposed to be Ben's character from earlier, though Ben could play him again and get transferred to another character after he gets killed. That leaves too many characters not getting played... I mean, Han and Chewwy are both playable in addition to the 5 characters already mentioned, and I think Han definitely has to be a PC.
I feel like Leia would be a fine NPC for Episode IV, as she barely does anything in that movie that requires being a PC. She does spend the first part of the movie captured and the last part hoping everyone else will succeed, which would be pretty boring to RP.