I am trying to work on one for my wife. You can do the initial phases online until all your documents and evidence are approved and then they would send the case to Bangkok.
Pretty sure you would get better advice in another group that is specifically for US Visas. But I would say if you live in Thailand then you should be able to apply online through USCIS website and when interview time comes use the American Embassy in Bangkok or Chang Mai.
I don't know for sure. People say Ed Visas always draw more attention from Immigration. If you can find a job that may be more suitable or keep doing border runs and 60 day tourist visas until Immingration shuts you down. There are people on here who have lived here for years doing that. Anyway good luck.