I used to play a lot of magic. We have a hobby shop down here without much else to do, so I would compete in tournaments and such. I would suggest changing your deck to mono-green, mainly because control isn't what you're aiming for with a ramp/overrun deck, and there are more valuable spells to put in there.
Also, I think you should run around 21-23 land, rather than the base twenty. I find that even in a green deck, it's okay to run 23 mana. Instead of aiming for a "big" creature end-game, I would suggest -Spearbreaker, -infect junk, -sylvan ranger, -frontier guide, +global ramp spells, +cheap elves.
Also, get your hands on some wellwishers and capitalize on your elves. More elves like Imperious perfect and ezuri would be great if you decide to run elves as the majority. Vorinclex is pretty great, though. I see a pretty solid deck here, so remember that these are just suggestions.
You can take some advice and leave the rest of it, or go in a completely different direction. Oh, one afterthought: Do you have any Garruks? He's a pretty cheap planeswalker... and a reusable overrun.