you may find some banks in Thailand decline to open an account for you if you are on a visa-exempt stamp. Some banks will turm you away even with a 90-day Non-O visa. So upon arrival, start bank-shopping right away.
What is the process of submitting a new TM30 upon eeturning to one's Bkk residence from a trip to elsewhere in Thailand? If staying with friends or family who don't bother to file a TM30 while you're visiting, it isn't necessary to have another one filed upon returning to Bkk home base, correct?