Great, I’d be interested in how you feel about Clippy’s eye tracking (and other features) after some time. The hardest thing for me is to remember not to grab the mouse.
Clippy doesn’t quite do what you want (multiple hotkeys for separate keyboards/registers), though it could with minor adjustments. The code is very well organized. To paste your 2nd last item: ctrl+shift+V, alt, 2 (alt+2 also works). 3rd last item: ctrl+shift+V, alt, 3. ctrl+shift+V opens the popup, alt shows the popup menu, and number keys choose an items. Also you can do ctrl+shift+V, down, enter. The “lock order” checkbox (shown after pressing alt) can be useful when using the number keys a lot, so the items keep their same number keys.