I want to see everything! lol. I am rereading it right now & don't know what would be cut. I definitely want to see Bella's "before" car, the Wedding, Isle Esme, more of Seth (the BEST werewolf!), Bella as a vamp & her first hunt, & the cottage Bella gets for her B-day. (That's where I"m at in the book right now.)
I think a good ending for part 1 would be Edward fighting to keep Bella alive & Jacob imprinting on Renesmee. I think not knowing if Bella lives is a really good cliffhanger. (So basically the end of Jacob's book.) I think part 2 should start with Bella as a vamp. Kind of like it's the start of her immortal life with Edward.