Short answer no. You need to keep the 800kthb in the account. So don't spend it.
Your option, if this is your budget, is to rent and then you can use the 800kthb after you have switched in one year.... Remember that the 800 kthb is for that first year...
that is what I did too. Had a non o a and immigration recommendations was to kill that by going to Malaysia and return on a extemt and convert that when I got back
no. 12* 65k in a bank account. I did have an income letter to but they wanted that verified in Bangkok so I showed the bankbook. They wanted a letter from the Thai bank that the money was transferred from abroad.