Venser, Shaper Savant and Mystic Snake are nice to cast twice or thrice.

Sun Quan, Lord of Wu is a must for this... there's not many horsemanship seeing frequent play...

You really should put in a Primeval Titan , so you can fetch some utility lands like Urborg, Tomb of Yawgmoth and maybe get some creatures who happen to have swampwalk. And bouncing him isn't all that bad. primetime is dropping in price, so it won't be that hard to find under $15-12...

Shardless Agent looks like a fine addition to this deck, grabbing you either an unblockable creature or some card advantage (it could also cascade into Artful Dodge and Ghostform , which would be unfortunate, but that's a risk you take with cascade)

Demonic Tutor , Vampiric Tutor , Worldly Tutor , Fauna Shaman , why not...

Eternal Witness , why not...

I usually don't pick Ondu Giant over Farhaven Elf . Unless you get a signet on turn two, it will enter play a turn later...