This deck needs at least 24-25 lands if you want to play a 5 drop on 5 or have a consistent mana base. There are a few random cards out of place like
soul scar mage and insult//injury that need to become lands. Add in 4
cinder glade and 4
game trail and remove the timber gorges and a
mountain, that will give you a consistent mana base. I would consider a pair of
heart-piercer manticore to give you more "
fling" affects. Lastly, I would take a look at your curve and ask if there are better cards on different mana costs.
~iz