consider the fact your Thai friend that used to work for immigration, and now has a visa center makes money every year on your current business visa, but will only make a fee once in five years with the DTV. Is that really your friend, or just trying to keep a customer by telling a fib...lolol.
you are confusing TM30 with the 90 day report. You personally do not file a TM30, unless you own the condo you live in. Your landlord files the TM30 within 24 hours of you moving in.
if you are on more than 90 days, and less than a year on overstay, when you leave Thailand, you pay the fine, and are banned for one year yes, but if you are stopped, and not on your way to the airport to leave, you are arrested, and on deportation at your expense, you are banned for five years if less than a year overstay, and banned for ten years if over one year overstay. There is a difference between being caught, and whether you are on your way out of the country, or not.
Keep in mind that if you are stopped for any reason by the police, or immigration, you will be arrested, deported back to your home country at your expense, and banned from returning for 5 years. Immediately go to immigration, or leave the country.
it doesn't matter if you have a visa, or not. Just because a Thai embassy issues you a visa does not mean you will automatically be let into the country. Don't waste your money.
that is a bunch of BS. Immigration has not put out anything concerning proving what you are doing to re-enter the country, as many have been doing. The first 180 day entry stamp has not ended yet for those people staying in Thailand as the visa only became available July 15th. There have been people leaving, and coming back, as it is a multi-entry visa, and none of them have had to prove anything. Just because you've seen something on YouTube doesn't make it true, no matter who was interviewed.
Nothing happens unless you work in Thailand doing work in the country, not working remotely. Anyone telling you differently doesn't know what they are talking about. Nothing has changed in that respect in over 20 years, and it doesn't matter how long you've been in Thailand.
No, she can not do any volunteering when on a DTV, as she must have a work permit to even do free volunteering, and you can not get any work permit on a DTV.