Yes, and with four separate victory conditions according to Isaac, meaning you have no idea what that night kill ability was for.

Precisely. Vampires can be scum as much as anyone else, therefore I see no reason to target vampires above anyone else.

As someone who was a vampire in Isaac's last RPS game, I expect vampires suffer stat penalties if they go hungry. I have no idea how the night results are provided - as mentioned above, Artsapat was apparently entirely unaware that I had targeted him last Night, and while I obviously know who I targeted, I don't know against whom I was successful, and against whom I was not. Anyway, I'm inclined to believe that you felt drained because you were successfully targeted by a Night Action (probably one that decreased one or more of your stats) rather than because you were targeted with a failed night kill action.

Erm, no. That's straight from the opening post, which I recommend you reread. You'll notice that none of the other items "allegedly" or "supposedly" give you stat increases. The garlic soap is the only one with that caveat right in the description. And it's also the only one with no clear mechanical description of how it affects the game. Does it prevent you from being targeted by Undead? Does it prevent night kills? Does it give you a +1 bonus to and RPS roll against Undead? Doesn't say.