I sided with the Dawnguard and have gotten to the point where I'm supposed to enter the Soul Cairn. The thought of having part of my soul trapped doesn't appeal to me, and being able to get the Vampire lord perk achievement without starting a new playthrough would be nice, so…
1. Can I cure myself like I would regular vampirism; with Falion?
2. Does this shut down any of the Dawnguard main quest or side quests?