A. No, don't let this player play a crazy overpowered race. For one thing, first-time DMs shouldn't have to put up with that kind of thing. For another, played strictly by the rules, a vampire PC in Ravenloft is going to fail powers checks at such a phenomenal rate that there's virtually no chance of the player's keeping the character long enough to level once, let alone 8 times.
B. It's not clear to me where you're getting this vampire PC race, or where all this DR comes from, so I have no idea whether you're reading it wrong.
Now if you're certain it'll be fun for everyone, then I guess you might as well try it, but my "DM sense" tells me disaster is in the offing. It sounds to me like the player wants protection vs. character death, possibly the ability to say "nuh-uh" to the DM all the time, and perhaps "permission" to be evil.
I'd say it'd be better to ask the player what the root purpose of the vampire PC is and, judging by the answer, determine whether there's any point to trying to run this game, or whether instead you should start out with something a little easier to DM. Something a little more "by the book" and not immersed in a setting whose purpose is partly to mess with players' expectations in order to keep them guessing.
If you really can't talk the player out of having a vampire character in Ravenloft, then mandate the template class (linked above), and refuse to go easy on powers checks. To my mind, Ravenloft is about heroes persevering in a time and place of great evil; characters who turn into monsters that prey on the defenseless need to be NPCs.