A 90 day visa is a non immigrant visa. They are only extendable for a year if you meet the requirements.

A tourist visa is valid for 60 days but then so is a free visa exempt entry if your passport qualifies. Both are eligible for a 30 day extension (for most countries).

You wouldn’t qualify for spousal visa in the sense that one of the spouses isn’t Thai.

No. The extension is based on the initial visa, so mandatory insurance would be required.

The only way to get “off” a Non OA is to leave when it’s over and either get a Non O from a local embassy or enter visa exempt and convert in country.

Perhaps it would be best to state where you are in Thailand.

Purpose of travel is “ visit family”. Leave the departure fields blank. Don’t even click on them or they become mandatory

1. Yes you can change dates.

2. Will depend on the officer but usually just your passport, copy of DTV and your last boarding card

3. Each entry you get 180 days. In theory you can extend once but in practice immigration will make it really hard to do so it’s easier to bounce out and back.

If you’ve stayed for 90 consecutive days in Thailand you need to report to immigration. Each office will have slightly different requirements but it’s usually pretty quick to do a report.

That’s office dependent. Some will want to every time. Others will say they don’t need it. You’ll have to ask your office’s policy

They haven’t got a DTV yet. They got stamped in for 90 days on a visa waiver (Brazil and a few other countries get this).

Nope it’s an overstay stamp but fine waived as less than 24 hours.

Edited [re-read the post]

89 days after 25th Jul is 22nd Oct

You have a Brazilian passport (or another country that allows a 90 day visa waiver

The stamp in Thai underneath translates to something like “overstay but fine waived as less than 24 hours”.