There are a few problems, even if I think it's a pretty solid theory
- If Leia appears in the film not-in-evil-garb, how will she hide the mechanical parts? I guess w/ skin like Luke, but then why take it off when she's being evil?
- If Leia does not appear earlier in the film, the graverobber's identity will be obvious. Everyone knows Carrie Fischer's in this film.