Run Sea-Gate Wreckage instead of
Haven of the Spirit Dragon. Haven has no targets in your deck, so you get no advantage out of its ability to provide any colored mana, nor do you have any Dragons or Ugins to rebuy. Sea-Gate Wreckage provides the same colorless mana as Haven, but also packs a nifty card draw ability for if you run out of cards in hand.
Consider a copy or four of
Blighted Fen. This deck is aggro focused, and as such will likely end up with too many lands every so often. Fen provides colorless mana when you need it, and an Edict effect when you've gotten enough mana.