Is there a limit on the number of days you can stay in Thailand with 30-day exemptions and SETV/METV?

You can stay until an IO says you can't. Clear as mud?

Somebody from a Travel Agency in Penang who organizes VISA Runs on a daily basis has told me that you can get up to 3 SETV's/year from there, on the same passport. With all the extensions that makes 9 months/year. On the other hand, the consulate in Penang told me that, because I already had 6 SETVs and 2 VOA's in my 3 yr old passport (that's an average of 2 SETV/year), I might get a red-flag the next time I apply for a SETV. This leads me to believe that, by average, 2 SETV's/year is the optimal number permitted that raises no eyebrows. (unless you have other Visa Exempt Stamps or VOA's)

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.

There is NO official rule about it.

The only rule is you can ONLY do TWO 30 day visa exempt entries by a land border in a calendar year.

There is no official rule about how many 30 day visa exempt entries you can get by flying in.

There is also no official rule about how many tourist visas you can get in a period of time either. The thai consulates have their own rule about how many you can get from them before you get the warning stamp.

Visa Exepmpt 30 days, SETV 60 days and METV 60 days on each entry. All three can be extended once with 30 days at local Immigration.