The change was actually a closing of a loophole, which "tax agents" in Thailand have jumped on and started fear-mongering amongst expats, in the pursuit of business. Sadly, many have been duped and subsequently scammed into handing over large sums of money unnecessarily
That's a personal choice. Some tax offices are more aware of the process and will not issue tax ID to those who are not required to submit a tax return at that office.
Actually your narrative is not easy to follow. Money has to be brought into Thailand to be "remitted income" so it's difficult to understand what point you're trying to make
ATM withdrawals and credit card purchases are deemed as "remittances" - whether they are taxed or not is another matter, as that depends on individual circumstances