The springs will be for your weight. The suspension is adjustable but if it is not sprung for your weight it is a total waste. Jason is a good guy and knows what he is doing.
it is still used on the 07-08. I did mine, it did help. I know on the 07-08 they did not make any power above about 12000 rps, the jumper opens the exhaust valev up to it still makes power all the way up.
you would have to put different bulbs in it as the one in them now only have one coil in them. there is no real high and low beam bulb just one has a reflector in it. This would involve a rewire and I am not sure if there are bulbs that would just fit into the headlight without moding it.
Dude don't be sorry, you don't have to change how you drive to make this ass hat be an idiot. I sure as hell would not get out of his way or give him the room to act stupid. This does not mean that I would chase him down or crash him but I would not change my driving to let him get through.
He is right and you will see people do it time after time. It is nice when you are trying to make a pass on the person and they swing wide like that then you can just blast bast them.