One of the big problems with the pream ghoul blood is the fact that you have too many glyphs to juggle.
Normally in blood you take deathstrike darkdeath and Drw
However now you drop DRW and have to take either ghoul or unholy blight
No ghoul means that you hae a very underpowered pet, which defeats the point of taking it if it hits like a flannel than dies
No unholy blight means small ticks, and as you are keeping this up all fight the damage difference glyphed versus no glyphed is gonna be big, the longer the fight the bigger
You are trying to combine to many elements from too many trees, overall you are just gonna weaken all the aspects of the class. Going deep into one tree brings out te best elements of that spec, in bloods case 10% arp, extra damage and a very powerful cooldown if you know how to use it