Ok, I'll throw my hat into the ring. Since his walking animation and many of the dumb looking moves like his old BAir, DSmash, and Dair were changed to fit the character better, here's some other things I think they should do to keep it consistent:
Moves that should be changed because they're stupid/unfitting:
-USmash (his head getting huge looks ****ing stupid, turn it into an uppercut)
-Nair
-UThrow (the upwards power throw from Wario Land 4 would be much better)
Moves that should have their animation overhauled:
-FTilt (just smoothen the animation)
-Jab (same as FTilt)
-Utilt (same as above but closed fists also)
-Dtilt (should be close fist instead of poking. more brute strength)
-Pummel (needs to be a hard punch or the shake animation from WL:SD, either one is better than a stupid little poke)
-Dash Attack (could be changed to resemble the sliding pose when you crouch after being launched in WL:SD)
-FSmash (The arm flapping during the end lag looks stupid)
Moves that are unfitting but should be kept because they're integral to his playstyle:
-B (Giant head/chewing people looks dumb and he's never done anything like this before, if this could be seamlessly changed to a regular command grab it should)
-UpB (A special move that's not based on anything)
-DownB (Wario farting is ****ing dumb. I don't care what you think, Sakurai made this up out of nothing and the fact that it's caught on as something people think is important to Wario's character is a crying shame. Unfortunately it's a really useful move in PM and removing it would change the character too much.)
Other animations:
-Air dodge (Spinning in place looks silly, make it more like Mario's)
-Sleeping (Should be a closer pose to Mario's, like in SM64DS, looks silly that he just kind of rotates onto his back)
-Double jump (should curl up into a ball and flip, like when you double jump backwards in Smash 4)
-Turning around while running (Still has the Brawl style running animation and it looks terrible)
New voices:
-"Have a rotten day" on Bthrow (from Wario World)
-"Oh boy" when getting hit hard (from Wario Land 4)
-"Boomshakalaka" or "Oh baby" when Dair is landed (both from Mario Kart 8)
-"I lost! To a bunch of losers" when getting Star KO'd (from Mario Kart 7)
-"Yeah! Take that, losers!" on the motorbike victory screen (from Mario Kart 7)
-"Wario: The Legend" on flexing victory screen (from Mario Kart 8)
New Taunts:
-Lifting dumbells (based on Wario Land 4 idle pose)
-Skipping (base on Wario Land 4 idle pose)
-Throwing out a big thumbs up with "Excellent!' (from Wario World) on it (based on the victory screen from Wario Land 2)