I miss read your post, yes convert the visa exempt to a 90 day Non-O. Hope I don't confuse you (or me). I have read that once you have the Non-O issued for the purposes of seeking a retirement visa/marriage immigration can lrovide you with a document specifically for the banks indicating that you require the account for residential purposes thus enabling you to open an account (have a look at previous posts in relation to Bangkok Bank issues - i think the guy who rums this site provided that info)
I may be wrong here but I was under the impression you needed to enter on a Non-O visa (applied for outside of Thailand). I doubt any bank will now open an account when you're on a tourist visa. The Non-O visa then allows time to open an account and allow for the funds to be in your account for the required time period.
Well it's not false as it's potentially true, as I say it depends on circumstances with tax paid at the income source and the income won't be generated within Thailand.
People on a DTV do not generate income from Thailand/Thai busnisses. Any income made by a person on a DTV comes from overseas streams. Is it subject to tax regulations within Thailand, well that depends on a number of circumstances, firstly the person needs to be resident in Thailand for 180 days or more, the DTV currently permits the visa holder to remain in the country for up to 180 days. You post is difficult to understand, the DTV visa is a longer term version of a tourist visa and does not permit the holder to a work permit and potentially cannot be issued a tax number or be liable for tax in Thailand but of course certain circumstances will dictate that.
Destination Thailand Visa (DTV) is categorized as a special type of tourist visa.
While it permits long-term stays of up to 180 days per entry (with the possibility of a one-time extension per stay) and allows multiple entries over its five-year validity, it does not authorize holders to work for Thai companies or obtain a Thai work permit.
This means DTV holders can work remotely for foreign employers or as freelancers with international clients but are prohibited from engaging in employment within Thailand.