The regulations concerning visas has changed recently. Check the Thai consulate website for your home country for the latest information. But basically, it used to be possible to come to Thailand on a 30-day entry stamp, take a bus to the nearest border on the day the stamp expired, leave, get stamped in and out of the other country, and walk right back into Thailand, because they would give you another ninety days. Some people had been doing this for seven years. Now you can only get a total of ninety days in a 180 day period, so you have to go to a Thai consulate in another country and apply for a visitors visa.

You can't own property, although you can buy a condominium. Many men buy property in their Thai wife's name, but when they break up, she gets to keep everything because it is in her name. It's the only reasonably fair thing in Thai marriage law.