Ask your school as all fees are different

@Mart ****

You can work "remotely" from Thailand but your business cannot have and customers based in Thailand.

All the steps to get married in Thailand are detailed here -

@John *******

Ok so you can read but cannot understand what the risk is which which is explained on the Overstay Form (number 27 in the list) you sign at some Immigration Offices when you get your extension. "In the case that the alien is apprehended

Overstay for less than one year

forbidden from entering the kingdon for 5 years".

Go on overstay for as little as one day and if you get stopped in a police checkpoint or bar raid and asked to produce your passport (a low risk but still a risk) then the above applies. 5 years blacklisted, simple enough for you?

@Michael *****

Your 30 days started when you got stamped in, that was day 1 (not day zero) so your 30 days stay included 29 nights, not 30.

@John *******

so you can't read

@Gary *******

The Non-O is the retirement visa, what follows is a 12 month Extension of Stay, not a visa or visa extension as your visa is over and stamped "USED" when you enter Thailand.

@Darin *******

No mandatory insurance for a marriage visa

@Max *******

if the landlord permits, yes

Yes, enter at the 6 month expiry to get a new 60 days plus the extension potentially gives you almost 9 months in Thailand. A 90 day stay is an entry stamp, an extension stamp and an exit stamp (unless you can use the new e-gates) plus remember your entry and exit stamp to another country when border bouncing and their entry visa (if not eVisa) normally fills one page.