To start, I have to ask about your FNM environment. How frequently have you been/played at your current LGS? Are people there laid back home-brewers or are you normally encountering people ramping up for the next Grand Prix/Pro-Tour Qualifier/StarCityGames Open? The reason I ask is because unorthodox decks like this can be a lot of fun and can work in the less competitive environments, but if you're going to be playing against a ton of net-deckers who are just running tier 1 lists, well, you're going to lose... a lot.
So I'm guessing the main idea here is to try and capitalize on the counters provided by Advocate of the Beast. This is a tempting strategy, but not one that I'm entirely sure will be the most competitive. In the event that the opponent takes out the advocates, you're really just sitting on a few sub-optimal creatures.
Gladecover Scout and Witchstalker are good pieces care of hexproof, but if you're wanting to go hexproof auras, you would be much better suited to go G/W to include fun things like Ethereal Armor, Unflinching Courage and Fleecemane Lion (nevermind tossing Heliod in there as he makes enchantment creatures with his cleric tokens). Outside of an aura-centric build, Gladecover Scout really just doesn't get the job done - you would be better swapping them to Elvish Mystics to at least help with some ramping.
Deadly Recluse also isn't half bad, but it's a purely defensive creature in a deck that, as it appears to me, is meant to try and take advantage of some speed and aggression.
Tuskers are good, so run with that...
Advocate of the Beast if he's central to the plan, why not 4x of him?
Rumbling Baloth is decent given what you're running with here, but let me ask, which sounds better, a vanilla 4/4 for four, or a 5/5 with scavenge for four, or perhaps a 5/5 with monstrosity that can take out opposing creatures for four? In this case, you would lose the synergy with Advocate, but Deadbridge Goliath or Polukranos, World Eater is a better choice at the four drop. Toss in 2-3 Nylea, God of the Hunt and now you're giving them trample and going to town.
Kalonian Hydra is good, but you would obviously do well to have more than 1.
Giant Growth has been a great spell for years and I certainly wouldn't want to begrudge it, but in the same breath, combat tricks outside of bloodrush aren't very common in standard these days, and even among bloodrush, Ghor-Clan Rampager is the only one that sees much play because it pumps AND gives trample. You would be better suited with some sort of removal here, I'm thinking Pit Fight makes about as much sense as you really can in standard. Perhaps Giant Growth is the best option as a sort of pseudo removal...
Naturalize as a 4x in the mainboard? Auras are more common in Theros standard than they have been for a while, but I don't know that it warrants four in the main... nevermind that you really want Fade into Antiquity to be able to exile the gods in the event they ever hit the field. In either event, I would slide all these to the sideboard.
Hunt the Weak is not bad, but considering that it's sorcery speed and costs four, you'd be better suited with Pit Fight.
Enlarge is good and might even warrant being at 3x.
The enchantments probably don't need to be in here. On the one hand, if you're going hexproof auras, you might have something, but outside of that, auras are typically bad as they present an easy opportunity for the opponent to two-for-one you. Alpha Authority might provide hexproof, but honestly, you'd be better just going with creatures that already have it or things like Fleecemane Lion that can be given hexproof in response to some other action.
Hopefully that much makes sense... now I'll give a list of a few cards you're going to want to look into for a mono-green build that should be useful.
Polukranos, World Eater; Nykthos, Shrine to Nyx; Arbor Colossus; Boon Satyr; Deadbridge Goliath; Nylea, God of the Hunt; Garruk, Caller of Beasts; Karametra's Acolyte... there are more, but I'm blanking at the moment...
I hope some of this helps. Sadly FNMs are frequently not as much fun for home-brewers in many respects unless the environment is right. So to that end, give all of this mess a look-through and pick out what you can work with, but most importantly, don't be afraid to spend a bit or go exploring to see if another LGS is more welcoming.
Good luck!