Wow that's a lot. I think a lot of that makes a very strong case for addon support, but doesn't really make sense as a default UI. Especially the items that talk about custom backgrounds and borders. Some other bits, such as the camera ideas, are perhaps user interface in strict terms but not really what I'm trying to compile here.
As I said, you've got some great ideas for the default UI, such as hotkeys to show/hide UI objects. I'll pick some and add here (and attribute them of course) and when the suggestions forum goes live next week, I'd suggest making a separate thread for things like your no-UI mode and customizable camera behavior ideas.