Can the cop do this? The cop did this. That seems to answer the question.

You say the cop had no reason, but then said it was for rolling a stop sign. The cop will say he cut you a break by not giving you a ticket. Not...

No, there is no grounds for a lawsuit here.............

Sounds like a good way to get killed..............

Of course not. They didn't entrap you. If you are charged with stealing hire an attorney.

If they live in your state you can sue them in small claims court.

My guess is you will still be charged, but none of us knows.

Yes. If they made a mistake you don't get a windfall. You still have to pay.

Not sure what you are investigating, and why. Call CPS. Let them investigate.

It is pretty much like performing surgery on yourself. Not impossible, but the result isn't going to be good.