its nice to see a vampire deck, that isn't using Edgar.
About the deck itself, you will get a tempo problem. You've got more than enough lands, but no mana ramp. Here some Suggestions:
Fellwar Stone,
Mind Stone,
Rakdos Locket,
Rakdos Signet,
Sol Ring,
Talisman of IndulgenceFor 4 of these you can cut lands without running into any trouble. The most important, at least for me, are the
Sol Ring and the Signet.
Then you could improve your mana base without spending alot of money:
Reliquary TowerRogue's PassageTainted PeakMyriad LandscapeCommand TowerMolten SlagheapSmoldering Marsh Depending on the Mana Base of your playgroup, you could also add Ghost Quater, or if you want to spend a little more money
Tectonic Edge (unless you want to play competetive or got some land destruction combos, i see no Reason to spend more money for
Wasteland or
Strip Mine).
Then about your removal:
Curtains' Call is very great in EDH. In stead of
Murder you could also play
Bedevil or
Hero's Downfall (both are around 2-3€ if I remember right).
Rakdos Charm could also come handy because its very flexible. If you got trouble with artifacts,
Vandalblast could be interesting. In stead of
Cast Down I would use
Price of Fame, because your oppontens commanders are often a more interesting target than the non-legendary ones.
I haven't checked the vampires in detail, but I think my imput already helps alot to improve the deck.