Star Wars: Rogue One - 10 Simple Blunders That Would Ruin It
10. Unmask Vader (Or Have Him Battle-Damaged To The Same Extent)
Growing up, the one image from the original trilogy I could never shake was the unmasked Vader from the end of Jedi. I clearly wasn't alone, because that fascination bled through into plenty EU events; Vader was constantly unmasking for his own enjoyment or getting into scraps that blasted off most of the helmet, revealing the fleshy Anakin underneath (implying there's a factory on Coruscant with a specialised Vader mask conveyor belt).
This most pertinently happened in The Force Unleashed, a disappointing hack 'n' slash game that likewise tried (and failed) to tell an interesting pre-A New Hope story. At the end (well, one ending - there's a very binary light/dark side choice before the final boss), Vader is battered within an inch of his life and looks positively action-figureable. It would be very tempting for Rogue One to repeat this trick somehow, perhaps even to explain his lack of agility during the Obi-Wan fight on the Death Star (and make action figures).
But to ever do this blatantly disregards the canon and what makes Darth Vader such a striking figure even after the prequels. In Revenge Of The Sith Anakin needs that suit to even breath and thirty years later in Return Of The Jedi Luke still says Vader will die if he takes his mask off. Maybe we should follow that implicit, original-trilogy-canon explanation? Yes, in The Empire Strikes Back he's chilling in his chamber without a helmet, but the respirator mask was still attached (and who wants to see something even approaching Hayden Christensen).