I’m not a teacher but I’ve been out in Thailand 12 years. I live here partly on a UK Teachers pension though.
Teaching can pay dismally here (£600 / Month) or reasonably (£900 / month) when you factor in the cost of living. However there is no free health care for you or any of your family other than what the school may offer as a package. Bear in mind that even that cover could be worthless in certain circumstances. I was married to a UK teacher and the amount of ridiculous work and responsibility they place on the profession I’m not surprised anyone would want out. The kids here do as they are told first time they are instructed so you will find the classroom less stressful. Add to that the parents / grandparents / step parents and the next doors neighbour won’t be challenging you at the gates because you tore Sirichai a strip off for hitting another pupil.
You haven’t mentioned which part of Thailand you would be considering, your choice will affect the school you teach in as well as where you live and the facilities available. You and your partner will not be accruing any funds towards your pension, neither the Teachers scheme nor the UK National Insurance contribution scheme. If you stay here whilst your children are growing up I can honestly say you own children’s education will suffer in certain subjects. Thailand is a very insular country and tends to work on the basis that only what happens in Thailand is important.
Living here is not like being here for a holiday. The country has the second worst vehicle fatality and accident record in the world and the air pollution is unhealthy. If you’ve been here and stayed in a hotel and thought the food was delicious then be prepared to either spend a lot on imported food or be unable to eat half of what you will be presented with. It’s not that it is too spicy, just some of the flavours are crazy and a good deal of it unhealthy; being unable to read what is in your food is a red flag to me.
Finally , the bureaucracy. I won’t venture into all the details but believe me they love to make things difficult here for foreigners and don’t believe the school will always help you out. Certain classes of visa require you to have cash deposited in the bank and for you to have a minimum for a certain time prior and after your visa renewal. You have to go to the bank and get a letter stating you have said cash in the bank. I’ve been denied visa because I have had too little in the bank and also too much money in an account. I once obtained my bank letter on a Friday afternoon and presented it with my application on a Monday morning. Once again visa denied as they wanted an 'up to date’ bank letter. If you think that is a problem then consider that the rules state the letter can be up to 7 days prior to your application, but each person you will meet out here will have their own interpretation of those ‘rules’.
I run a business out here and live with Thailand’s problems but also benefit from the many great aspects of living here, but beware it’s not all roses. Just try it for 1 year.