I think this deck may finally be in a decent state.
The main change here is to try and fit the deck into Modern from its previously casual-only playstyle. Gonna go through the changes based on creatures, noncreatures and lands.
Creatures:
Removing Wild-Field Scarecrows and adding a fourth Scuttlemutt. May consider re-fitting them into the deck at some point, since they are a decent early wall early on and synergize better with the new mana base since it focuses on basic lands.
Lands:
Removed the artifact lands, replacing them with basic lands for now. (again, trying to make the deck modern-legal. Plus, the artifact lands didn't actually add much to the deck.)
added a playset Academy Ruins. Having another 'scarecrone-lite' method of returning your spooks is huge for this deck, just in case your opponent catches onto what you're doing.
Noncreatures:
Removed the playset of Unstable Mutation. Really cute and fun interaction with Grim Poppet, but sometimes just don't need it (you can just put them on your own guys then bring them back with scarecrone/academy ruins). I'll keep them in the sideboard for now though, since it can actually be insanely useful when up against decks that spam either 1/1 tokens or indestructible foes.
Removed Tinker, replacing it with three Fabricates and one Gifts Ungiven. Even though it works wonders in this deck, I have found it no longer necessary. No more will I be the A-hole who brings tinker to a casual game night!
Removed the Sol Rings and added a full playset of Lotus Blooms. I've recently discovered that Lotus bloom makes this deck absolutely ridiculous under the right circumstances (more ridiculous than even tinker).