All you have to be able to do is hit 7.5bps with each hand anyway nowerdays, or if you psp'ing then one finger ftw.
To train walking a trigger, just simply tap your two fingers alternatively, the main focus is that you are alternating between the two, put on a CD, tap on the desk for a song or two once a day, focusing on keeping them going alternatively, and you can train each hand in no time, gradually upping your speed.
Also, RE the, I can shoot like a billion balls per second, its all bounce and fancy electronics, nothing else