Is Vampirism Actually Useful for Stealthy Archers?
Solution 1:
- Yes you can contract it multiple times
- You advance a stage each in-game day you do not feed.
- No, you have penalties at all stages, they are just extreme at the fourth stage.
- I would say no but this may just be my personal bent on the situation.
Unless its for RP reasons, the penalties (specifically the regeneration issues when out during the day) make this status not worth it in my opinion. It would seem a better use of your items/blessings to just directly improve your stealth instead of having to try and compensate for this manner of doing so.
You can get more detailed information on Vampirism here: http://www.uesp.net/wiki/Skyrim:Vampirism
Solution 2:
1) I would do a quest to kill vampires or something to contract it (If you go to Falkreath, there's a quest from the blacksmith for you to get him a dog on the road, it leads to the Daedric quest, 'A Daedra's Best Friend', you follow the dog into a cave with vampires and vampire thralls.).
2) You advance to the fourth stage of vampirism after about 3 days, without feeding on a sleeping NPC.
3) Yes there are actually penalties. When you reach the fourth stage, you'll notice the little spot where it grants your abilities, it'll say something like 'You are now hated and feared', meaning everyone in-game will attack you on sight.
4) I wouldn't bother with the +Sneak it gives, I suggest you just find items with enchantments, or enchant it yourself.