The "employment prohibited" might be for potential Thai employers, not for immigration authorities. When a Thai company is doing their employment verification process, they'll check your visa to see if you have employment authorization. You'll give them your foreign passport during the hiring process and they'll see you can't be legally hired on the sticker visa in your passport.
I saw it in this group. Someone had applied for a DTV in his home country but already had travel plan to Thailand. Didn't get approval before he left and just traveled to Thailand anyway, probably planning to do a border bounce. I actually can't find the post anymore, so maybe he deleted it, but he received an email from the embassy asking whether he was still in his home country. He didn't know how to respond, and the other commenters said you shouldn't lie to consular officers. No, it's not proven, but probably a lot of the posts here are true, even if not verifiable.
You're not supposed to do this. Just be aware that the consulate has some resources to check your entry record to Thailand. Some people have entered Thailand during their application processing period with no problems, but there have been some reports of people being detected and having their application invalidated.
Hi, Do you think supplying so many documents might have delayed acceptance of your application? I see that you have an Australian bank account and a Thai bank account, but the Thai bank account was over 500k baht. Maybe you could have transferred the money to the Australian bank account and they wouldn't have questioned you about having a Thai income source.
Probably any properly licensed dental clinic. Depends where you want to live. Just choose one with a good reputation. But I actually had begun treatment with a dentist prior to applying for the DTV. Also, I'm not familiar with all the embassies' policies, so I can't guarantee any outcome. But I'd say you'd have to focus on bolstering other parts of your application, like your financials, to feel more confident in your outcome. Some members here say that Jakarta is an easy embassy, but I don't know, as I didn't apply there.
I was at Taipei last week. I had a medical tourism app but ended up combining with a remote worker application. They seemed to focus on getting a good picture of where your money's coming from. I only provided 3 months of bank statements, but I provided income info from further back. I don't know if I would have been approved if I just said I was living off savings--probably would have required longer period of bank statements.