I agree with everything said, though the drop-down-and-die problem could also be fixed with little notification bubbles appearing on the edges of the screen.
There's also the fact that when you press Jump/Attack at the same time, you will jump and the Attack-SFX will play, however neither an animation nor a hitbox is thrown out; so either remove the SFX or add hitbox + animation.
Edit: Aerial Shuriken don't use meter.