If you're going to be playing mad vampires then i'd encourage having both creatures and spells that let you get madness triggers on a consistent basis. For example:
call the bloodline gives you a creature (with
lifelink), that creature is a VAMPIRE (which works with the deck theme), and it gives you a chance for a madness trigger. That is three really good effects all in one. Also
Elusive tormentor is a good one that when it transforms becomes unblockable, hexproof, AND indestructible. Again three in one utility card. Stuff like that which will help the deck flow more easily and not get clogged up at the wrong times.
Also another thing i'm seeing is like two different deck strategies going on here. There are the aggressive vampires that attack, get stronger and have the madness capability. But then i'm seeing a lot of sacrifice cards. If you're having trouble deciding between the two it'd probably be best to make two separate decks. This way you can see how all of your strategies will play out and you won't have too much going on in the same deck. Just an idea that may assist you in the future.