Some countries issue Wise debit cards which you can bring to Thailand but it's better to use Wise to send the money from home into a Thai bank account as the exchange rate is about half a point better than major banks.
It depends on who you get. I was told 1 extension per year and got away with 2 visa runs but only 1 extension and was questioned at the airport and told to buy a ticket within 7 days but avoided that when i told them i have a Thai wife and daughter. Then i got the right visa but was still held up when i returned as there must have been something put into the system.