About those 2 with Starwaffle, i'll give it a try:
From Banjo kazooie?May be Mumbo house?
No but damn it do I want to make some Banjo Kazooie stages!
Hmm. Phantom Gannon's battle area?
No but holy [censored] that would be an epic stage. I think Mewtwo should take care of that along with the other Zelda boss rooms. He did a great job on Ganondorf's Tower so he deserves to do it. This was discussed in his thread a while back, to do a combination of all Boss rooms in one stage, but most likely the file size limit is gonna be an issue.
About my collab with Starwaffle on the 2 stages , keyword is stages, nobody has guessed yet.