you can definitely do two visa-exempt entries and also two extensions Yet everything after this is upon the discretion of the immigration officer at the border
the owner of the premises has to report you on the Immigration within 24 hours of your arrival on the location. He/she needs the blue housebook and his/her Thai ID card . . . .. He/She could also register her house/apartment in the Online TM30 system. They will receive a Login-name and a password, and will be able to make an online TM30 for you upon your arrival
it's valid if there are no longer periods in between each stay. It's however limited to two entries by land border per calendar year . . and last but least it is always up to the discretion of the officer at the entry point
. . and after two visa-exempt entries by air, when doing a third one, you might get pulled aside and questioned about your intentions.
You might be asked for the famous three proofs: 20,000.- THB in cash (or in another major currency), proof of accommodation and proof of onward travel within the 30 days you will get stamped in upon a visa-exempt entry
If you can show all of the above you will be let in, however you will hear them say “you stay in Thailand too long, get a proper visa the next time!”
Sometimes they even put down a small secret mark into the entry stamp, so if you attempt a fourth visa-exempt entry within a short period, another officer will see that you already have been warned
I don't use an agent, I got the 800,000.- THB and do everything by myself. Many agents will offer their service for you, depending where in Thailand you are.
well, if it does not arrive in your Email-box until the day of departure, just fly without a visa (but watch out that the Airline can ask you for an onward-travel proof within the 30 days you get stamped in upon a visa-exempt entry). In case the visa arrives at a later date while you are already in Thailand, NOTE that ou can activate the visa any time with a simple "border run"