now the question was for initial visa it seems to me: so for non-O 90 days visa for retirement you need to prove that money came from my abroad. For the extensions you do not need to prove that.
there are more forms to fill in... But it's free. In bkk they didn't complain for me. But it was a different person who first did the movie, i think. Maybe the person who prescreened it. Then the new stamp was added.
Safest is to get a one year statement!. At least Bangkok bank will skip transactions in the bankobook if you have many, then they can't prove you didn't go below...
It takes 5 days to get the one year statement, needs to be ordered from the headoffice.