I didn’t like the movie mostly because the rebel characters are totally inexistent and underdeveloped (and the alliance representation is lame as ever – rebels who don’t want to rebel because the Empire is too powerful… seriously…) and there is no pacing at all (I’ve never been so bored in front of a SW flick…), but the Empire is not that “damaged” (well, Krennic is too weak for someone called « director » but this is something that can be changed thanks to fanediting), so, instead of a complete reworking of the movie I would suggest to only keep (minus some modifications) the Empire material. No rebels, no Yavin IV, no Erso, nothing, except at the very end when they attack (so no “rebellion are built on hope” bullshit). Just Krennic, Tarkin, Vader, father Erso. Some kind of an one hour prologue to ANH. A few other things could be changed to reference the clone wars when the prologue starts (in an opening crawl, adding that the intro sequence is set a few years after the end of the clone wars and the foundation of the first galactic empire), and it should work. Obviously Tarkin will still be cartoonish and Vader will still be Jason Voorhees (unless the ending sequence is also removed entirely), but I believe it can save a few scenes.

Other idea: why not adding this to the end of a heavily fanedited ROTS version? Or with ROTS material used as flashbacks ?