I would suggest writing your desires to explore the Thailand culture and its different cities of the Kingdom and your love for whichever soft power course you have chosen. Write that you plan to travel to explore other SE Asia countries in between courses maybe?

Im sure I remember seeing a post from someone recently on one of these groups that had theirs cancelled because of leaving the country they had applied in before it was approved.

Anonymous participant 341 you dont have to fill that question in

Yes thats absolutely fine.

Oh sorry for the misinformation. Last time i visited it was 14days

If you apply in Vietnam be sure to get a lomger visa than the 14days exemption. Because it has been known to be taking some time to be processed and you could run the risk of overstaying to stay there or having to leave and in doing so potentially forfeit the DTV approval

I guess its open to interpretation as it is for the IO. I could easily tour around Thailand for 6 months. 1month in each major city/island. I travelled for 10months a few years ago and 4months total of that was Thailand. Warnings and checks dont necessarily mean being refused or denied a visa. And they dont seem to have recieved any yet. So probability says they will see this person is a frequent traveller to Thailand. Has always followed the rules and not overstayed and is following the rules by applying for the correct visa.

Anonymous participant should be no reason why not. More and more are now being questioned when they have done 'too many' border runs but there still isnt a limit for air travel as far as I know. Its more just frowned upon amd they will tell you to apply for a proper visa this is if you are a serious misuser. From your description it doesnt sound like you have been. But if this is your first time this year and you dont over stay your 45 days and genuinely leave for a little while, applying for a single entry visa for 60days is the right thing to do and it shows you are following the rules and not trying to misuse border runs.

You could apply for the single entry 60 days and then extend it another 30dl days thats then the 3months of the money being in your account. Then leave the country to apply for the DTV?

Maybe try to apply for a multiple entry visa instead? If you get that and use it correvtly you then prove you can follow the rules and legitimate visitor, then after a successful multi entry use you may be more successful with a DTV?