Ok, so I completed the questline on the DG side.
1) If I let Serena turn me into a VL, can I still convince her to cure herself? (I did all the proper dialogue options before, I just wanna know if her turning me and her curing herself can both be done)
2) I have a pretty invested character (leveled in the 80's, tons of hours/progress), but think he would be more suitable as a VL on the Vampire side. Can I just delete the DG add-on and download it again, and basically just choose the Vampire option? I'm on 360, btw. Will my save be fine? Will my items from DG stay there as long as I both delete AND redownload without loading the save?