On vampires:
With faith: Faith is a very strong tool, but why is it that a simple cross can hurt a vampire. You can't just will one away from you. I feel that I have strong faith, enough to influence my life, but I doubt that I could repel a vampire with it alone. It makes sense that faith plus cross repels a vampire (assuming you have faith in what the cross represents). Hmmm...
With water: My understanding was that a vampire cannot cross running water. This is a common theory with a lot of undead or evil creatures. Water itself isn't deadly, so they could get caught in a rain storm with no ill effects (Not even a cold!). Perhaps the flowing water is flowing life? But then raining life would be just as bad. This is one I've never been able to understand.
