I play something somewhat similar, but with a little more control and therefore less creatures. I would really recommend Temporal Spring. The fact that it is a sorcery doesn't matter much since I'll want to play it before combat to trigger my Shorecrasher Mimic. The fact that it can bounce lands AND disturb opponents next draw gives me quite a tempo advantage. Jhessian Infiltrator also triggers the mimic while helping out if opponent has some heavy defenses. I'd like to have Noble Hierarchs instead of the birds, but they're out of my price range.
Ah Temporal Spring, I've only ever thought of it in context to another deck I, it seems like it would fit very well in here. I'll probably cut the Mulldrifters for it.
I find that running 8 mana dorks let's me bypass most two drops. I tested the hell out of Jhessian Infiltrator, and while I really liked her, she was overpowered by a turn two Rhox War Monk and basically every other 3 drop in the deck.
The acceleration can be crazy in this deck and I find that most two drops outside of Shorecrasher Mimic don't have that large an effect on the game.