List of Resistance Changes:
Grass should resist Steel: If you throw a metal can on some grass, the grass won't stop growing. It'll just keep growing over it as the metal itself can't harm plants. It'd also make Fire/Water/Grass/Electric all resistant to steel and resisted by dragon.
Edit: yes, axes and lawnmowers exist, but that's with a person using the steel to actually do work. If you just place the steel there by itself it won't do much damage
Ice should resist Heart and Flying: Agree, see reasoning above (143). We could also let ice resist grass but grass is already bad enough...
Bug should no longer be resisted by Fairy: Agree - what logic says fairies are unbothered by annoying bugs? However, bug should still be resisted by poison (too toxic), fighting (for the resist duo), and ghost (already dead)
Psychic should be no longer resisted by Steel: This is the most controversial... but in gen 6, dark and ghost, which function similarly as psychic (e.g. using brainpower/spirits) hit steel neutrally, so why not add psychic as well? Psychic is bad defensively, so why make it just as bad offensively, resisted by the omnipresent defensive type steel? The resist was added in gen 2 to balance out broken psychics, but they're no longer broken. One side effect though is Psychic/Bug is unresisted, which might cause cm/recover/psychic/signal beam psychic types to become too overpowered.
Move Changes:
Reduce accuracy of toxic used by non-poison types
Power Gem --> 90 BP, 10% chance to drop opponent SpD
Focus Miss, Hydro Pump --> 110 BP, 85% acc
Shadow Claw --> 80 BP, keep high crit rate
Aura Sphere --> 90 BP
Moonblast --> 90 BP, 20% chance to drop opponent SpA
Dragon Pulse --> 90 BP
New moves:
Rock-type Hurricane clone, 100% acc in sand
Poison-type Draco Meteor clone
Psychic-type Superpower clone