There are many Burmese agents who provide the services which include for opening the bank account in Thai banks. If you are not met the requirements to open the bank account, translators can’t help you but only for interpretation service.
You are right that you dont need to change your passport unless some emoloyer ask to do. This is how MM authorities want to do but nothing to do with your emoloyer in Thailnd. Mandatory requirements of PJ passport to apply work permit us specifically for those who has contracted under MOU process.
As long as you are white color job offered you, not mandatory to change your pp at this stage.