Vampires can be pg-13, as long as they are played in an appropriate way. As for the costs, I'm thinking the usual vampire weaknesses- Can't go over naturallly running water (any river, stream, lake, or ocean whose direction wasn't changed by mankind), sensitivity to garlic, can't stand sunlight, holy symbols, or Micheal Jackson songs. Each drawback would be instant effect, offsetting the abilities of the Vampire.
I knows mees undeads. :ugeek: