Pit's arrows belong at the very top, but at least Pit is already an archer so its understandable he should be actively using projectiles, except you can say the same about Ness or Samus and their projectiles aren't over the top. (Very top.)
Olimar's Pikmin Throw is definitely up there because it hikes up Olimar's already solid camping that works off of the grab range. Though you can punch through the Pikmin and get Olimar somewhat. Still, it deserves any hate for it a little more than Pit's arrows does too, because it spends Pikmin lives like water, which I believe goes against Olimar's character or whatnot. That wouldn't even be a problem if the Pikmin maturity stages did something, preferably with leaf Pikmin being worse off than what we have so that flower Pikmin don't make Olimar overpowered. (Lower TOP just out of spite of basically turning Olimar into
Zero.)
Grenades.......up there with versatility, but they come slowly, so it's not like they're uber. Oh, speaking of Snake, I checked out his tilt horizontal ranges using Battlefield's small platforms: the forward tilt's reach is about 90% of the platform, and the up tilt is about 70%. I see why they can be dangerous, but I wouldn't outright gamebreaking. Oh, and the disjoints must have been intended; I also tested for diagonal disjoint with the up tilt, and there is virtually none. (Upper high.)
Din's Fire is up there again, this time for sheer power. But it's slow so it can be dodged. (Upper high.)
Diddy's bananas......the instant trip for being hit can be very abusive, and it certainly make no sense. Slipping because of a banana peel should happen because your foot touched it, not because your torso touched it. The grounded one should already be sufficient as a form of stage control, especially when Diddy is already a close range demon. (Mid top, again out of spite against this.)