Here is what is missing:
Global menu bar: A concept in user interface design where a system-wide widget on the screen displays the menu items (also known as “actions” in Qt) for all applications I've tried “actions” in Qt and is not at all the same feel.
A positional "sane" mapping of keys. I swap left ctrl and left alt in Linux. Alt on a PC keyboard is positioned where the Command Key would be. I install AutoKey to map all of the Alt keys to Ctrl keys in the Terminal: this is so my left Alt+c (Ctrl+c) will Copy (Command C) by sending ctrl+shift+c, and my left Ctrl+c (Alt+c) will send ctrl+c (break) to the Terminal.
As far as I can tell, textbox navigation keys, like Home and End "PC" behaviour, are hard-coded in X11. Command ( + Shift) + arrow keys navigation in a textbox does not work as I expect, and cannot be configurated, I would need to modify the X11 source code and build from scratch.