Found it and it's already fixed: my buttons now hide along with the game's, and the animation keeps playing while they're gone, so you can watch it on a clean screen. It'll be in the next version.
Your three things are really one thing, and it's the right idea.
The 300 backup slots are baked into the game's own save, so I can't stretch that number. What I can do is give the mod its own library that holds as many characters as you want and loads them into those 300 in pages - and that library is also where your folders would live ("Sam" with his outfits, "Show1" and "Show2" kept apart). It's a big piece of work, so I won't put a date on it, but it's on the list.
The outfit list is the easiest of the three and I want it myself. A character is one long code, and the clothing part of that code is a section I can read on its own, so "put this outfit on that character" is copying that section across. I think you'll get that one before the folders.
Don't apologise for the list. It's the most useful comment I've had.