Just a few questions about it and if it'll effect my game

1. How would I uninstall it and would I have to pay 1600 MSP to get it again?

2. If I uninstall it, would I have to redo any of the quests?

3. Would I regain any lost items once I reinstall it? (e.g. If I had an upgraded crossbow, would I get the same crossbow back?)

Only reason I'm uninstalling it is so I can get the alchemy lab in Breezehome.

1)Once you've bought it, you've bought it. Should be able to go to your Marketplace purchases and redownload when you want.

2)Yes. Uninstalling it removes it from the game, any save game you load will be absent the content (You'll get a warning message about missing content). Reinstalling will simply be as if you were installing Dawnguard for the first time. Though reinstalling and loading a save game from just before the uninstall will allow you to continue from where you left off. But thus defeating the purpose of the uninstall in the first place as any save you make will be without Dawnguard content.

3)No. If you uninstall, you lose everything. Reinstalling will not give you items back, you'd have to re earn them all over again.

Be wary of this Op. I have uninstalled Dawnguard and now my old save is unplayable. Whenever I go to save it freezes my whole system up.

Hm. I'll just keep DG installed and build my own house in Falkreath when Hearthfire comes out. Thanks for the info, though.