So the banned list looks something like:
Mario Galaxy - Giant and walkoffs
Mario Circuit (Brawl) - Walkoffs and disruptive hazards.
Luigi's Mansion - Circle camping and teching
Wooly World - Giant with walkoffs for half the stage.
Yoshi's Island (Melee) - Walkoffs and other stuff.
Jungle Hijinx - Circle camping?
75m - Everything.
Gamer - Over powered hazard.
Temple - Circle camping cave of life mess
Bridge of Eldin - Giant with walkoffs and a giant hole in the center for a long time
Pyrosphere - Ridley
Norfair - Lava
Great Cave Offensive - Giant with instakills.
Port Town Aero Dive - Hazards will kill you instantly.
Onett - Walkoffs and car hazards and promotes camping
Coliseum - Walkoffs and Giant. If only it had edges.
Flat Zone 2 - Wrecks your **** with hazards and walkoffs.
Palutena's Temple - Holy **** man everything.
Skyworld - Cave of life and no grabbable edges when platforms are broken.
Boxing Ring - Giant, walkoffs, and powerful stage hazard in lights that respawns super fast.
Wii Fit Studio - Big, walkoffs.
Gaur Plain - Stage boss, walkoffs, circle camping when no boss.
Wily Castle - Yellow Devil ruins everything.
Pac-Land - Scrolling walkoffs.
Possibly OK:
Mushroom Kingdom U - Depends on how hard Nabbit is to kill / if his OHKO can be shaken out of.
Pokemon Stadium 2 - The problems that were seen in Brawl could be fixed.
The conveyor belts mostly are.
Garden of Hope - While the crab does 20%, there's no knockback. It's a little big but that's possibly not an issue.
Wrecking Crew - The barrels might be hard to get out of.