Wow, ... I mean kudos.... this list is amazing.
I really like your ideas... and another is that the superball had only 1 attack everytime. For example: Samus Shoots a big laser than goes into zero suit. Everytime, over and over.
Oops forgot to mention that, I meant to put that on the list to
Ability to turn stage hazards and items off.
Edit: Superbot doesn't seem to be wasting development time on useless content. Remember coin launcher, stickers, and the craptastic stage builder? Not to mention how awful the Subspace Emissary was. That was a huge pain in the arse to complete.
This is mostly just my opinion, some of you might like that stuff.