Imo this deck should work very well with some help of Riding Camps. At the moment you're focused on massive unit control (Bloodletter and a lot of damaging things) But i'm not sure about Shrine to Nurgle and Melekh. Generally no single unit can stand against Bloodletters ability. Following this, an opponent units are more likely supposed to be destroyed than corrupted ;)
Rest seems to be okay. But do you have in your mind to put Elite Moulder Clan into this deck? They're far more dangerous than Servants of Khorne, and Rats are great distraction, cuz an opponent is used to neutralize them as soon as possible.
But it's my subjective opinion ;)

thanks, forgot to consider restrictions ;)
what do u think of the deck? haven't tried it yet.

You can not put Warpstone Excavation and Innovation together in same deck 'cause of restrictions. Drop innovation for Unleashing the Spell. Nowdays it's a greatest chaos finisher, especially combined with Light of Morrslieb.