Regarding the teacher who asked on Ajarn how difficult it would be to find work at 60 with no degree, my university asks for a Masters but accepts Bachelors. I know this as I only have a Bachelors myself. However, at 60, he is probably too old to be accepted, but they will keep people on after 60 if you are already in the system and on the payroll. The problem universities have is that their job promotion is poor, and they advertise the salary they are allowed to by the government. However, most positions have many extra ways of making cash, such as marking exams, grading essays, and attending events.
I know people who are 60 years old and over working in shopping malls in Nonthaburi. As long as you look presentable and can deliver classes they don't care too much about age. If someone younger interviews at the same time then you will probably lose out, but in Nonthaburi there are lots of malls and not so many NES teachers.