use common sense. It is only 5 months old. No one knows the answers to your questions, not even immigration. It hasn't even reached the point where it can be extended. You get 180 days on each entry for five years.
I've been doing it for the last 9 years. If you don't have a work permit they want to see that the bt40,000+ each month came from an overseas source. For the type O extension based on Thai wife they don't care where the bt400,000 came from, but because you are not legally working in Thailand they want to see that the bt40,000+ came from outside of Thailand.
so you think they don't? Guess again. They share that data with US immigration too, and have access to US immigration entry, and exit data, as they do with most every country in the world.
actually the Thai embassy can simply look at immigration records, that they have access to, to find out what country you are in very easily. They are computerized after all, and do check. Find a way to stay there until your DTV is issued.
The requirements are getting stricter as time goes by, and they recognize the abuses people are doing to scam the system. This is how Thailand operates with anything new like this visa.
As long as you've got the equivalent of bt500,000 in your personal bank account you should be fine. You might be asked for your latest income tax filing though. The embassy in Yangon Myanmar is fast.