Here are the cards I'd cut:
1. Collective Defiance - You have enough draw, and do you really want to copy this?
2. Gauntlet of Might - Hit mountains so duals other people run benefit from this. You have so much ramp do you really need THAT much?
3. Pyromancer's Guantlet - you only have a few red burn spells and do you need them to do 2 more damage? Plus how often are you going to use Chandra's to shoot for damage?
4. Staff of Nin - You have so much draw and is the 1 damage once around the turn worth it?
5. Mind Moil - Talked about this. Seems iffy in an artifact heavy deck.
6. Pyrohemia - Seems sluggish. Has some synergy with other items in the list, but once you're able to wipe the board with it, you're going to spending about the same mana and the enchantment will still just die, plus it's harder to get back later.
7. Sulforic Vapors - less good than Pyromancer's Guantlets and is harder to bring back.
8. Tectonic Instability - Seems counteractive to a couple  other enchantments you want to run more.