I work security and have a lot of cop friends. I can answer these questions for you.
1. Stop when you see the blue light unless it is entirely too dangerous or it is at night and lighting is bad.
2. Yes good idea. Besure he can see both of your hands all all time and do not make sudden unexpected movements.
3. Correct do not change.
4. Always play dumb. "Really?! I had no idea I was going that fast. I was just listening to my radio and didn't notice." It'll get you off with a warning most of the time.