Thai banks may not only require a certificate of residence to open a bank account. Some require in addition a long term lease or yellow book. Research your preferred bank’s requirements.
Yes the Thai tax year follows the calendar year so as long as you don’t spend 180 days in a calendar year within Thailand you will not become tax resident.
that’s exactly how it previously worked for many years. Now the same process produces a different result which is what everyone is complaining about. Now it doesn’t code as an international transfer in the receiving Thai bank.