Jeez, that's quite a list.

There are other, simpler ways of doing a lot of that stuff. If you want accented characters, enable the Compose key.

E.g. https://www.setphaserstostun.org/posts/setting-the-compose-k...

If you want Mac-style keystrokes, try Kinto: https://github.com/rbreaves/kinto

But there are other ways: https://medium.com/@petrstepanov/a-macos-like-keyboard-remap...

Me, I use old Apple mechanical keyboards on my Macs, and IBM mechanical keyboards on my PCs. The different feel engages different muscle memory, and I use Cmd-C etc on macOS and Ctrl-C on Linux without thinking about it. For terminal emulators, use Ctrl+Shift+C etc. I personally find this a much simpler solution, but YMMV.

If you want an easier life, dump GNOME. I've tried every blasted desktop out there and XFCE makes my life easier and happier than any of them.