Yes only b-king, not on busa.
Get ecu editor(or someone who has it)and turn the gearing and top speed restrictions off(there is alot more power hiding in there).
That exhaust valve will not be in an aftermarket exhaust. It's only there to make the throttle less agressive.
It can be removed without harming anything.
If it is the same as the gsxr's then one wire needs to be removed from the ecu and the pin taped up, to prevent the fi light from staying on. You should be able to find the info at b-king.org without having to join too.