Very well formulated and concentrated list!
It’s just so much information that I find it hard to absorb it, all while considering if it could break some existing workflows that I would object to. But nothing major comes to mind apart from:
If all would be implemented it would result in a very complex modifier setup. Lots of different moves/click-drags etc.
That does cause quite a lot of concern. We are close to the technical modifier limit already.
CTRL/ALT/SHIFT there is just three of them. I use CMD a lot as I am a mac user. But Windows doesn’t seem to appreciate the WIN key being used in the same way.
Apart from that I think a few are genius, some are very good, some are not for me and some a bit to convoluted, but still conceptually interesting.