2. No, just a room without windows where no on can disturbe them, they are sensitive to noise so don't have them share rooms.
3. I have, since the vacation NPC's you have to learn stuff from like gestures, dances etc remain on community lots until around midnight you simply have your Vampire sleep during the day and go out aftre 6 pm. The only vacation memories they really can't fulfill are the "Got a Tan" memory (if there is one don't remember). It is no different than taking any other Sim on vacation.
There's not a "got a tan" memory but there is a "sunbathe" want they can roll. Although you can still have them sunbathe at night it will still fulfill the want, which I find somewhat silly but that's how it goes.
I believe there was an old episode of the Adam's Family in which they went moonbathing. I think they were also mindful of moonburns.
(Of course, scientifically speaking, moonlight is sunlight reflected off the moon since the moon doesn't emit light. So perhaps they're just getting a very small dosage of sunlight that's still healthy for them? )
I don't mind if you call me "MSD" or something for short.