This moveset is REALLY good. I'm impressed. I only have one minor gripe with it. Plasm Wraith's neutral B, Needle Arm, seems more like an infinite jab with a finisher than a neutral B. As an alternative, you could have Dwarf Bulborb be the Neutral B.
It could spit out a small blob of it's own goop, which lands right in front of it, then forms into a Dwarf Bulborb, which will walk around, and if it walks near a foe, it will bite it, doing about the same damage as Bowser Jr's forward tilt. It can block attacks, and will dissolve into goop after walking around for 10 seconds. But hey, that's just an idea. I'd love for Plasm Wraith to get in anyways, and Smash is in DIRE NEED of more villains.