Especially with the number of mana rocks you play, mass land destruction seems pretty solid: armageddon, cataclysm, boom//bust. Flagstones helps than too. I would also add some more duals instead of basics to the mana base. Anger is also kind of weak if you don't have entomb to search for it and put it directly into your graveyard. I would play web of war instead.
My deck started out a lot like yours, and transformed into what I have now through recommendations and experiences from other people combined with problems I encountered on my own through play testing, so I would say just go to my thread and read all of the comments. Deck link in sig.