You can come and go as much as you like on either the 90 day Non-O visa or any extension of that visa provided you have purchased a re-entry permit from immigration before you leave Thailand. A re-entry permit does exactly what it says, it allows you to re-enter Thailand on your current visa or extension (it means you don't lose it when you leave as you otherwise would). You can be both single use or multiple use re-entry permits, multiple allows you to come and go as much as you want for the duration of your visa or extension.

@Wayne ********

no you can't. You can only get a Non-OA visa in your home country

@Mark ********

to say you are still alive

@John ********

if you are married to a Thai the financial requirements for a Non-O based on marriage are lower, plus if you decide you want to work in Thailand at some point you can get a work permit on that. The Non-O based on being over 50 doesn't allow you to hold a work permit, needs more money in the bank, but has a much simpler renewal process

@Arshaad ********

soft power covers things like Thai boxing, Thai cooking etc but you still need to have at least 500k in the bank

@John *****

get a multiple re-entry permit and come and go as much as you want

Yes you can convert from a DTV to a retirement visa just the same as you can from any tourist entry. Visit your local immigration office and ask for the requirements but generally you will need 800k baht in a Thai bank account in your name only and between 15 and 21 days left on your current stamp depending on location to do so

Every application costs the same so if you apply for your kids you need to pay the fee for each of them

No. At least not unless you qualify for one of the soft power options. But to be honest the Non-O visa based on being over 50 is easy and no need to leave the country

@Monair *******

yes if you get the Non-O visa or an extension of it in Thailand. A Non-OA visa allows you to keep your money in your home country for the duration of the visa but has additional requirements such as compulsory insurance, background check, etc