I have a Logitech G402, and it has 4 extra mouse buttons on the sides. I am currently using 2 of them as shift and cntrl to slow-mo and roll respectively. I am curious whether are mouse binds like this are allowed.

Yes key bindings are allowed as long as they are 1 to 1 binds. No binding one button to multiple keys.

Ah I see, thanks a lot!