"visited about his law breaking", get a life. It is there choice if they do not wish to wear seatbelts (as a driver). The police have much bigger issues to deal with that some idiot parking LEGALLY.
Middle finger doesn't help this situation, however much you feel inclined to use it. It would quite possibly work against you because the police could see it as a form of aggression/abuse/intimidation. You have to take the moral high ground.
You clearly didn't brake hard and you sped up once he moved into your lane to make him a lot closer than he would have been. Your speed clearly also shows you breaking the speed limit... Well done
Drivers are going round stealing exhausts from cars. If you see them give em a friendly welcome by smashing their car in