if a police officer pulls you over then asks you for ID...?

If you're in charge of a motor vehicle on the public road, then you are legally required to carry documentation to prove you are entitled to drive that vehicle and present it to anybody who has a legal requirement to ask - in this case a police officer.

If you refuse, then you would be detained until such time as your identity could be confirmed. Whether the situation is resolved at the roadside or involves you being taken into custody is largely down to how cooperative you are.

A police officer is not required to tell you why you were stopped before demanding ID. Yes, you can be arrested if your state has a Failure to ID law.

You have the right to argue the reason for the stop in court, not on the street.

just show them your driver's license, and insurance. if you try to make things difficult by insisting you know your rights and object to being stopped you can work your way into a ride to the jail

Yes. Explaining the reason for the stop, while certainly good practice, is not a necessary condition for arrest.

It's not the ID that is the issue. If you are operating a car, you have to have proof that you have passed the required tests. It's that proof you're being asked for.

Yes. You need to provide ID if you are pulled over.