Accessing the system APIs have no use in alone. The solution should work out of the box without hacking for ages.
Using scripts works out of the box without hacking for ages as well. You only need to write the script once, and then share it with the world. This is the point I made in other comments already which you read but ignored the point.
I know from experience that scripts do not work out of the box. Often times their syntax is nontrivial. I also know quite few limitations of xmodmap/xev keymaps and autohotkey. Using a configuration application does work out of the box.