Anonymous participant 667 because it hasn’t happened to you doesn’t mean it isn’t happening to anyone. There are plenty of reports here about being questioned when entering the country.
Absolutely not. They’ll just copy your passport, ask you to sign a million documents, spend an hour of your time, charge you 400 baht, and give you a new card.
People used to do border runs to Ranong. Easily done in a day. My neighbour in Hua Hin did it multiple times. Whether or not that’s still a thing I have no idea.