As I've stated in my question, there is already xkb which already has alot options for modifying the keyboard. It wasn't an option for me because the only option to modify the printscr key, replaced it with Win_R. Gunnar Hjalmarsson on this thread suggested to me that I modify xkb's modifications so that the printscr/win_r would do printscr/menu instead. We worked out a solution together and I'm going to retransmit it here:
In terminal, enter:
sudo su nano /usr/share/X11/xkb/symbols/altwin At the bottom of the file you will find:
// Win is mapped to the PrtSc key (and the usual Win key). partial modifier_keys xkb_symbols "prtsc_rwin" { replace key <PRSC> { [ Super_R, Super_R ] }; modifier_map Mod4 { <PRSC>, <RWIN> }; }; Delete this section and replace it with this:
// Menu is mapped to the PrtSc key (and the usual Win key). partial modifier_keys xkb_symbols "prtsc_rwin" { replace key <PRSC> { [ Menu, Menu ] }; modifier_map Mod4 { <PRSC>, <MENU> }; }; To delete in nano, use backspace key (highlighting and deleting doesn't work). To paste, use shift-ctrl-v. To exit and save, press ctrl-x, select yes to overwrite and press enter.
Reboot. In Gnome/Ubuntu Go to gnome-tweak-tools In tweak tools go to Keyboard & Mouse section, press the Additional Layout Options button and expand Alt/Win key behavior. Selecting the option on the very bottom: Win is mapped to printscr (remember that we've modified just this behavior to swap print and Menu instead of print and Win). (I'm sure there is a way of turning on the modded xkb option in KDE but I don't use it, so I can't give you the exact procedure).