You are following a pattern of a tourist, visiting places around Thailand. Lots of people base out of Thailand when visiting other countries. You won't have any problems.

500k baht each.

If you are looking for a cooking class that qualifies, although they might want you to have an ED visa, is the cooking program at Kasetsart university. It is a degree program, and a full university.

@Graham *****

thanks. I wasn't aware of that. Forgot about the holiday.

@Pui ****

no matter, he still can't do anything until Monday, unless he crosses a border out of Thailand today.

This is related to the Microsoft IT issue affecting airlines worldwide the last two days, with many flight cancellations, it should be cleared up today, or by Monday. As such there is nothing you can do except pay the overstay fine, if they charge one, as Monday is the earliest you can visit immigration, resulting in an overstay anyway. Just ride it out, as it will be cleared up as fast as possible. A fix for the software problem has already been developed, and sent to those affected. How fast the systems catch up is not known at this time, but constantly check with your airline. I mean hourly checking. This happened worldwide on Friday, yesterday.

Tony Stan as of the 15th of July it is now unlimited. You are posting outdated info.

That 2 times crossing the land borders in a calendar year ended yesterday. It is now back to unlimited.

Contact the SS division of the US embassy in Manila in the Philippines. You can do it all by email. They handle all SS for all of lower South East Asia. It took me less than a week, and the charge for part B was not on my next payment. If you ever want to get back on part B there is a 10% penalty for each year you were off it. If you were off it for ten years then signed up again during the sign up period, usually in November, then the premium would be double, but that is the only penalty. Part A is free so you always have that, the in patient major medical part. If you stay out of the US for the rest of your life it is a waste to keep paying it as you can't use it.

Being out of the country for three months doesn't show a pattern of trying to live here long term as a tourist. You'll be fine.