I used to do this until SCB closed their branch at CW. Now I present a letter from SCB dated the day before I apply for my retirement extension, and have had no problems.
As always in Thailand when dealing with officials speak quietly, respectfully, and slowly. Dress well, and generally behave well. This won't solve every problem, but it will help your case.
I don't know about a lump sum but in terms of income I would say around 200k baht per month. It all depends in how you want to live in terms of accomodation, food and drink, social life, travel etc.
This coming from a govt which came into power in a very underhand way, and which is controlled behind the scenes by the same individual who brought in the restrictive, ridiculous alcohol laws.
As far as I know there are not new tax laws only the possible intention to more widely enforce existing laws. At this point it is unclear just how many people this may effect.
Many Chinese feel that Thailand is not safe. Reports of rape, robbery and murder in Thailand are widely reported in lurid detail in China. This is of far more importance to most Chinese than what the TAT describes as 'wanting high-quality tours and authentic local experiences'.
The GSB regularly provides a moratorium for debtors. It then provides more loans for the same stratum of the population who then go into debt all over again. It'a never-endjng cycle to keep the masses under control.
For us there is no eternity. Sooner or later our planet will be gone. Sooner if hit by an asteroid, later consumed by the Sun. In the meantime we should try to be kinder to each other, and kinder to our fellow species on Earth.
I willi ignore your sarcasm and simply point out that there are thousands if long term foreign residents in Thailand who are not on this, or any other forum, who have no knowledge whatsoever of the criteria/requirement for filing a tax return. Unless they are not formally told to file they will presumably not do so.