If 2 times border bounce by land this year, then you need to either go out and come back by air, or get a tourist visa rather than come back visa-exempt. Of the Thai consulates I've used, the one in Vientiane has always been pretty user-friendly. Penang is also okay, maybe depends where you are now and which is closest.

Cambodian visa is $USD30, but beware this border is notorious for over charging, usually demanding Thai baht equivalent of around $40 + some other BS $1-2 fees.

See

To stay 6 months you will need another plan. For example come in visa-exempt for 30 days, extend at immigration another 30, then go to Laos or other neighbour country and apply for tourist visa at Thai consulate, then come back for 60 days and extend another 30, etc. Staying more than a few months as a "tourist" is becoming increasingly difficult. Good luck.

If you've only had one tourist visa so far this year it should be okay to get another one at the Vientiane consulate. But no guarantees as it is always at the discretion of the officer in charge. Vientiane is usually pretty easy though. Good luck.

The days of staying indefinitely on back-to-back tourist visas or visa-exempt entries are OVER. If you want to stay long term, get a proper (Non-Imm) visa, which is attached to marriage (to Thai), retirement (over 50 with money), or a real job with supporting documentation.

OK then give a verifiable address, look up some actual guesthouse or hotel.

So what? Just give any address. Mango Guesthouse 123 Durian Street. Are they going to fact-check it?

Definite improvement on the old site, although they still have the wrong location for Chiang Mai office ;-)

Depends on where you are now and if you already have multiple tourist visas or visa-exempt entries. The Thai consulate in Vientiane is fairly user-friendly. From your list, however, I'd say Penang is a go. Also what passport do you carry?

Trim them down to size. Sometimes they even have scissors available at the waiting area.