I wouldn’t change Ren exposition and dialogues. It’s fine that there is barely no suspense about who he’s related to, otherwise it would be quite ridiculous. The main issues of the movie are internal ones, cutting a few weird dialogues would not deeply improve it, but that’s a start. The first things that should be removed in any subsequent fanedit would be the distracting fan service bits: space chess, Luke’s training ball, 12/14 parsec raid. It’s been 3 months since I’ve seen the movie so I don’t recall more little annoying bits; maybe the second Han/Leia dialogue which seemed forced and badly written, and the “who’s in charge Phasma” that can easily be cut entirely. There is also the map puzzle thing which was too long. Anyway, right now I’m more willing to watch a “conservative” fan edit (with only a few minutes cut) because we still don’t know what’s coming with Ep VIII & IX.