might have miss read a coule of cards. will do more testing when I can.

Well you seem to be lacking in flying defense. You could also use some recursion since your token production is only 8 cards I would personally drop the Arboreal Alliance since you are not producing that many tokens. And I know it is a way to use all the mana you can produce but you need some more reusable uses for the mana.

I spent most of this weekend testing your deck against some of mine which are also go wide strategies. And what I kept running into was that your ability to get damage through was struggling. I think you need to get some more sources of trample or bypassing defenders. Another problem I was having was you would be top decking to quickly.I felt it just kept running out of steam.

I personally would drop Arbor Elf for Argothian Elder. It may cost more mana but it would let you untap Nykthos without Yavimaya in play, drop Quirion Ranger for Seeker of Skybreak just a bit less hassle for untapping a creature. even though she gets an interesting trick when you have Ashaya out. I would also drop Woodland Bellower for the Skyshroud Poacher just because it is easier to reuse. Elvish Guidance can have its uses but I think Growing Rites of Itlimoc  ^Flip is still a bit more useful, for your mana outlet I would absolutely keep Staff of Domination over Thousand-Year Elixir. I am surprised you dropped both Dwynen, Gilt-Leaf Daen and Jagged-Scar Archers since those were your only real answers to flying maybe consider Raking Canopy or Gravity Well to help against flying heavy decks. Mobilize and Vitalize are a little too weak for the card slots I think. I think a couple of more useful options would actually be Taunting Elf, Nemesis Mask, and/or Tempting Licid of those 3 taunting elf is weakest. But what those would allow you to do is get your pumped up elves through with minimal losses and minimal investment for the finishing blow.

I do have more thoughts if you want but as always feedback on what you are aiming for always helps (EG: Going tall, going wide, elf ball, kill through combat, or focusing on I win effects (I don't like I win effects))