Yeah, you can fit some story in there, but unless they pull scifi shenanigans not normally seen in the show, there's a pretty hard limit presented... largely by River's stated age in the movie, I think.
As I've been sitting on it, I'm concerned with the Mal/Inara and Kaylee/Simon pairings. With no ability to effectively move in any direction, those relationships could become stale banter very fast.






