Have you considered splashing Blue for Meddling mage with the large amount of combo running around? It also can be quite helpful to stall B/W which can be problematic for most any deck. (You also get Brainstorm)
Yea I would consider that if I didn't beat B/W 2-0 in the last round and the quarterfinals for a total of 4-0. Plus, what do you take out? Nothing is bad enough to take out for mage. Also, brainstorm doesn't always get you lands like tithe.