I could add so much more functionality to my keyboard if I made shift, ctrl, and alt do something when pressed standalone. I was wondering if there was any way to do this software-wise in Arch Linux.
Assuming you're using X11 (via Xorg), there are two answers – one for making shortcuts which affect the keyboard itself, and one for everything else:
Xorg has ...
Using AutoHotKey (Thanks, JW0914; twice), I found a passable solution.
Solution works for Windows 10 (most scripts on Google don't!)
; -- This is where we block the normal key function (but not combinations) --
LWin & vk07::return
RWin & vk07::return
; -- This is where we override functionality --
Use Microsoft's Mouse and Keyboard Center to reassign keys as you like:
Download and install Mouse and Keyboard Center.
Connect the keyboard that you want to configure.
Start button → Microsoft Mouse and Keyboard Center
From the displayed list of key names, select the key you want to reassign.
In the command list of the key that you want to reassign, select ...