Only things I advise against on that list,
Mushrooms/Starman – Both of these could easily decide a match, and half the time spawn right next to someone/in their path giving them a free, large advantage.
Beam Sword/Home-Run Bat/Star Rod/Unira – Not because of their intended use, but they’re *edited*ing powerful when thrown at someone. Star Rod actually sends them at a downward angle I believe.
Fan – spam A, get lots of free damage, don’t get punished. It’s speed is too much to justify the damage.
Containers – Nothing sucks more than starting an attack, and an exploding capsule spawning in front of you before you swing, killing you for no reason. *edited* that.
Soccer Ball – really easy to kill things with, but it usually doesn’t fly where you want it to. Maybe this one doesn’t matter.
And the reason I mentioned stages is because DDD’s chaingrab = instant stock on any stage with a walk off boundary.
Other than that, it’s all cool.