Welcome to the forum! If you have never been there before, don't decide that it is delightful and relaxing until you have been there in high season.

spent last winter there, and have answers and/or opinions. As to your questions:

1) You can't buy property in Thailand, so the norm would be to rent the premises. You can buy a condominium, but that is all.j

2) I don't know how you would do that as expats. There are very strict rules (bent, of course, at a cost) about how a business must be structured. The business must be majority Thai owned, and under the new regulations, must have full access to all bank accounts, which could be a problem. I'm sure there is some lawyer that will work things out to protect your investment.

A co-op pretty much depends on the honesty of the participants. As a foreigner, I'd expect you to be taken to the cleaners.

3) I assume that is a book. If it has not been revised within the last year, none of it means much, as the rules have all changed and are in a constant state of flux.

4) I have never heard of anyone getting Thai investors. You are the rich farang.

5) You can only get a work permit if you find a job where your employer is willing to sponsor you (i.e. spend money and go through government hassle) and can prove that no Thai can be hired for the job. You can get a business visa, based on your purchase or establishment of a business. The easiest way is to marry a Thai, but then everything is in your name, and when (maybe if) you get dumped, the spouse owns everything.

Most expats with jobs teach English as a second language. It doesn't pay very well, just enough to get by. Qualified teachers work at international schools teaching subjects like math and third grade, and they get paid somewhat better. I do know an actor in Bangkok.

6) I never heard anyone express any interest in western theater.

Most expats who invest in businesses in foreign countries lose their money. If you are planning on investing money you can't afford to lose, you should think again.

There are probably ways around most things. After all, everyone in Chiang Mai has a drivers license, and no one has ever taken the test. They just pay for them. However, every time you get around a rule, you are going to be subject to future payments to keep from being found out. Even normal fees will mean extra payments.

Every expat I knew with a business in Thailand had a Thai spouse.

If it is possible to copy your business, it will be copied. If no one does, then you have to wonder about its viability.

I know you are all excited about this great new place, but think carefullly, and good luck.