Thanks - I would be interested to hear more details from anyone who has been asked for a tax return, as I'm unsure which of the requirements that would relate to.
could be fine for now as long as you've got decent health insurance and are happy living a relatively simple life - whether the maths still works in 10 / 20 / 30 years is another matter (Thailand is still a developing country so it's likely to become much more expensive over time)
If you've already opened the restaurant, I recommend you not to post about it online and instead hire an agent to arrange your visas ASAP, quietly.
Also note, you will need 4 Thai staff for each 1 foreign staff and there are various other restrictions that make it difficult to staff a restaurant with foreigners.
no - the way it's described sounds more aligned with financial evidence for tourist visas (i.e. bank account from the country where you apply for the visa is fine) rather than for extensions of stay for retirees (i.e. must keep a deposit in a Thai bank account)
it's better than either of those explanations - it's a visa that's valid for entry anytime within 5 years, which is valid for 180 days from entry, and extendable, by a further 180 days immediately after