In the Thai public schools, there are usually 2 levels. 1. Basic level. And a Second level for families who can afford to pay more. Not nearly as much as international schools. When we moved to Sattahip, we enrolled our daughter in the second level. There is a significant improvement over her former school.
Make sure to keep your last boarding pass. My last time in, officer asked to see my hotel booking. I've been asked to show hotel booking a couple of times.
I opened a bank account while on Visa exempt status in Pattaya @ Bangkok Bank. Merely needed a Thai to vouch for me and a Letter of Residency Letter I obtained from immigration in Jomtien. Also, they offered to open an account if I purchased their insurance first, without the immigration visit. Try going to a Bangkok Bank Branch in a high international tourist area like Asoke Sukhumvit Area.
Someone did a video article, where he asked young Thais, males and females, this question. The general answer was no. Either it was not paid. Paid and refunded. Or the bride and groom, both contributed, to come up with the amount.
I'm surprised after 2 years in Thailand, this is the first time you encountered a wacky foreigner. Now that the Covid restrictions are lifted, you will see a lot more.
My point is, you are more likely to be pulled aside if you have an expired "banned" or "overstay" stamp versus a clean passport. Note, I did state obtain a Visa before leaving her home country. Thus, not suggesting she try to sneak in. Just offering a suggestion to avoid extra scrutiny.