I want a setup where in my left hand I have a move navigation controller running through motionjoy, and in my left: a mouse. sort of like the splitfish fragfx but I don't want to get I know this can ...

In SetPoint you need to set the buttons to key presses that you don't use when you're playing. Like N, J, K, L, ;, etc. You can either do this for all applications, or figure out which .exe is running ...