this is a private website, not related with any embassy or Thai government institution, so I'd take with a grain of salt the information written there.
Also, I don't know if that's the same or a different person, but I read here about somebody who got it trhu a university course, but if I recall well, it was something culture/arts related, not language. (Might be a different person, tho).
the Embassy can grant the visa to anybody they want, under any premises, I'm not arguing that. But the written rules are clear. I wouldn't bother to try, or at least I'd ask beforehand to the Embassy I'm applying at if that's even possible. Remember that unlike offline applications, for online ones, once you apply and pay, there are no refunds no matter what.
Thai Language courses don't qualify for getting the DTV. About the money, I think only money deposited in regular accounts counts. Lastly, but not less important, remember you'll need to temporarily leave Thailand to apply for the visa at a Thai Embassy or consulate abroad, while you're physically waiting there.
Participante anónimo 102 No, many DTVers have already exited and reentered many times this year already. No questions asked, and just a new 180 days stamp upon each entry. So far it's facts, not assumptions. Not saying they wouldn't implement some changes in the future, tho.
Don't worry about in country extensions, you will never need one if you leave (and reenter) before any 180th day, which is pretty common, at least for the so-called digital nomads. I don't see many not having to visit any other country at least once for in more than 6 months.