Now either people are gonna hate this or they are gonna love it.
Personally i haven't seen any client that has something like this. My suggestion is to make key strokes have an advanced setting. Players can have the normal key strokes and if they want they can enable the advanced. What will the advanced have? Even more keystrokes...like half of the keyboard or something. It will be big...but people will me able to resize it whoever they like it. I would love to see something like it and im sure many people would like it too :>
(Also Mouse strokes pls <3)