Whampire venators are generally not a problem for screwing up the effort to make mortals forget the Oblivion enemies because they're not actually quite people. That said, Thomas personally being involved might actually be a problem since, as Mab put it, being in love makes him "mortal enough" for some purposes.
However, I'm not sure how well the venator agenda to keep wizards in the dark is actually working either, given that Carlos said being told about the Old Ones like the Sleeper is the last step of a formally trained apprentice's training.
I think Whampires are Mortal enough for the purposes of the Oblivion War. Otherwise there'd a lot less need for secrecy between them. And as you say, they are mortal enough for many purposes. Specifically, they seem mortal enough for those purposes that require mortal Free Will, like the Fae Knighthood or the Coins. /Bob/ didnt count, but Bob is in many ways a glorified MS Paperclip Dude; he wouldnt count any more than say a ghost would.
