Looks good! I always loved the idea of making a squirrel deck. I think the tricky part is actually keeping the numbers and potency of the tokens up.
Check out Swarmyard to make those critters more resilient.
Arbor elf would be good for Squirrel Nest, Swarmyard, and even just to get your expensive spells out sooner.
Something like Parallel Lives or Doubling Season HAS TO be in this deck.
Also look at Coat of Arms. All your tokens become Squirrel Mobs and all of your Squirrel Mobs become twice as strong.
You are also vulnerable to early aggression and flying. Something like Wall of Tanglecord might be the remedy.
Finally, the bane of this style is mass-removal (day of judgement and the like). Green isn't very good at dealing with instants, so the only thing I can really think to do is sideboard Birds of Paradise and Negate or something similar.
I've never seen a squirrel deck in action, but this way seems best to me.