Do visa stays in Thailand reset yearly, and what is the maximum duration for a tourist visa?

Sounds to me like you fully intend to stay 6 months at least. You are yet another useless person asking random people if you can get away with not getting a visa. You are the problem !

There is no reset.

A tourist visa does not guarantee entry, every entry is up to immigration

The longest period you can apply for depends on the visa. Tourist visa 60 days, Non-OA visa 365 days

Proof of location will depend on where you apply from

*** There is no "reset".

*** There is no mention of "calendar year".

*** There is no two-times limit on visa-exempt entries within a one-year period.

*** nothing "resets".

In case you have heard from out of the mouth of an Immigration officer such statements, this officer will soon learn that what he said isn’t true.

There are only two extensions possible on visa-exempt entries, within a one-year period.

The first extension will be issued for 30 days, the extension for a second visa-exempt entry will be issued for 7 days

You can theoretically do 4, 5 or even 6 visa exempt entries for short 2-3 weeks holidays, within a one-year period, if you never maximize each stay.

Of course, upon each entry, you should be able to proof your onward travel, a few nights of booked accomodation and proof of cash equivalent of 20,000 THB

*** the picture of the pink post in Ko Samui or the other picture from the border to Laos are telling you absolute rubbish. These pictures have been published in many group threads, and every group admin is warning you to NOT believe any of the drivel it contains

No idea about your questions.

It makes no sense to me.

Land border enters used to reset at new year.

At the moment there are no restrictions for enters.

1) up to the immigration officer. But probably fine as long as your stay in 2025 wasn't from October - December and then you try for an immediate 90 making it 180 back to back. Though you never said what type of stays, so you're not giving us complete information.

2) up to the immigration officer

3) you can "request" whatever you want, but that's not going to change how long a visa gives you. A tourist visa grants a 60 day tourist entry stamp.

4) utility bill with address, bank statement with address, drivers license with address, passport stamp showing when you entered a country.