Participant(e) anonyme ok, so you don't have a company. Do you have any registration from your country that you make business ? In my country when you are a self worker / freelance. you need to be registered, and you have a certificate/registration of that.
I think some people get the visa working for online platform, but be ready to accept it may failed.
( what I mean is if you do a "side business teacher", with no official / regular business , it may failed)
So if you don't have a company, or a business registration, you may failed to get dtv visa for work. ( or maybe you can get through .. note : 500k is the minimum amount, if you show them more and more it make your case stronger ( and maybe lucky that they dont check everything in details).
even stay 180 day "consecutive" may be problematic , the under rule is more about less than 60 days in the last 90 days ( some people get deny entry after 60 day and 1 week vietnam and comeback )
residency and permanent residency is not the same. Staying more than 6 month in Thailand make you Thailand resident. ( that does not mean you can stay forever ;) or give you any specific right )
You don't realy need to buy ticket, you can give flight number.
Personally I fill "to book" in the flight number, meaning I will book ticket after I get the visa... I get the visa no problem and book ticket same day š