You have a lot of decent cards listed but I think there are a few flaws here. First off I feel you could definitely use some more burn. I would take out some cards like the 1 of Feast of Blood, and even the 1 Kalitas and Kalastria Highborn. They are kind of weird fits based on the numbers of the other cards you have. You need Go for the Throats and/or Doom Blades. They are the most efficient burn this deck can use. Also in your sideboard I noticed you have a fair amount of Red cards - but you have no red mana! That won't do. Also cards like Markov Warlord are not good at all in constructed (limited mayhaps, but for constructed like this it is too expensive mana wise). I would put Dismembers in the sideboard for sure. I would look into some other Vampire lords like Bloodline Keeper or Vampire Nocturnus since you are pretty much running a mono black Vamp deck. Also Guul Draz Vampire
would be a good fit with cards like Bloodghast and Vampire Lacerator. Also the 1 of Verdant Catacombs doesn't make much sense to me either.
Now if you want to splash some red in this deck and go dual colors, you could add some cards like Stromkirk Noble
and Stromkirk Captain
, or even Rakish Heir
Sorry I threw a lot in this one post, but I hope some of this helps!
EDIT: Sorry I didn't auto card everything, but I think I autocarded anything that wasn't already here in the previous post.