I dunno man, I regularly copy partial screenshots and paste them into my gmail of all things and it works perfectly. Also pasting into GIMP, or pasting into Telegram. Similarly I paste text from the terminal into other programs.. honestly, where is the problem? My computer doesn't even have a middle-click button (trackpad) so I don't even remember about the X clipboard most of the time, it's a complete non-issue these days.

> consistent keyboard shortcuts

Apart from the terminal which obviously needs an alternative to Ctrl-C (same as Windows, and shift-ctrl-C beats shift-insert or whatever any day), and Emacs which is, you know, emacs, I can't think of any programs that do not consistently use Ctrl-C and Ctrl-V. So what are you referring to here?