I've had one for years and never had an issue using it in Thailand for purchases. You get a good exchange rate direct from Mastercard and no extra fees from the bank.
Car hire companies all around the world offloaded a lot of cars early on in COVID. Now either demand for hire cars returning, there is fewer around and the are charging a lot more for them.
lol if she's not an educated virgin, she's dreaming if she thinks you are paying 500,000THB to the family.
You shouldn't be paying a cent. If they insist on any on display it should be going back to you minus any wedding costs and a token amount of gold to the mother.