I don't agree at all. It's a sign of respect.
It's no different than answering a question with "Yes, sir." or "No, sir." The real problem comes if it's a female cop. ;-)
No, don't do anything until asked. Keep the papers where they are. If there is a gun in the car, it might be a good idea to tell the cop, now. If you're a FFL holder, he'll probably already know it.
Stupid is as stupid does.
Treating in a non-threatening way, and with respect goes a long way. It's a shit job, you don't have to make it worse.
You sound like you're going to end up with a hole in your head.
That's a jurisdictional thing. In most of Bluemerica, it would land you in prison for a good long while.