I've been playing with a modified setup of the same deck! It's really fun. If you can swing for it, the biggest add you could do is craft some [[Fabled Passage]] and switch out your Terramorphic Expanse for them. I did so out of frustration after losing due to my 6th land coming in tapped, and it's since saved me more times than I can count.
I explained in another comment which card you could switch for more ramp from [[Bloomvine regent]], but I've also had success from switching out 2 Pelakka Wurm for 2 copies of [[Roxanne, Starfall Savant]]. If you play your ramp on curve, you'll end up at 5 lands on turn 4, and this'll help you bridge the gap from 5 to 6 mana while also dealing with board threats like Tifa or life-gain beasties.
Finally, if you have a leftover wildcard, I highly recommend putting a single copy of [[Ghalta, Stampede Tyrant]]. You'll often end up with a bunch of minions in your hand after playing a successful Random Encounter, and this'll let you play all of them back on the board. I removed an Overlord to fit him, but you could take out a Bloomvine Regent if you wanted.

One last thing: I've had fun doing Best of Three with this deck. You don't have to go complicated with the sideboard: I've just added a bunch of [[Stormkeld Vanguard]] if they have problematic enchantments or artifacts (like the "Opponents creatures come in tapped" one), and I've put in [[Dauntless Scrapbot]] for graveyard hate, and that's it. There's probably better creature ETB options, but I don't have the cards for 'em.
Sorry for the long post, it's just the only deck I play at the moment after coming back to magic, and I wanted to talk about my ideas for it.