Fair play. I was fairly sure that coming from abroad needs a new TM30. But then I don't live in CM and am basing this on Jomtien....so many offices are different. I know if you want an extension of a visa you need a new one there (Jomtien)..
Yes but she called the authorities and pretty much invited them into her home to check on her immigration status.......LOL :) In general if not extending, there is no need to do the TM30.
I would happily live with my conscience if it means not going to immigration every time I go and visit another province. Why do more than you need to. I am not sure about Phuket, but it is not enforced in most other places. Also you really only need to register the TM 30 if you will be going into an office for an extension or other reason. Otherwise if not visiting an office, there will be no fines or consequences.