Non O is a lot simpler, but seems your doctor isn't very helpful, he doesn't even know you well enough to sign off on those 5 specific diseases? Maybe time for a change.
Usually the visa application location has to match with your passport home and/or address home, so if you submitted a US passport and/or a US home address then they probably want you to apply at the Thai embassy or consulate that's nearest to that location, if you supply a Spain passport and Spain address then they'll ask for everything from Spain. You can't mix and match. Same goes for background check etc.
you will need a multiple entry visa or apply for a reentry permit B4 you depart. Otherwise if you leave on a std single entry visa it will be void on departure, regardless of the length of stay remaining.
except it cost you the use and earning power of 800K for 4-6 months of the year. Which is probably more than the agents fee if invested in a good annuity or mutual fund.
well yeah...you don't need an agent for all that prelim stuff, just to avoid the 800K and 90 day reports and standing in line with 20 copies of nonsense
Doubtful the bank would issue the proof letter on a frozen account...but if you unfroze it then it's probably ok cuz you satisfied the time and amount requirements.