No, there is no limit on either work permits or the number of non-B visas you can have.  There is only a limit (officially) on the number of teaching licence waivers, but many teachers have managed to work for years using these waivers. 

Several readers have suggested paying a visit to your embassy in Thailand and getting a sworn affidavit. It certainly worked for them when they were faced with the same situation of the name on their degree not quite matching the name in their passport.

Please note though that the British Embassy in Thailand no longer provides this service. 

Ask ten different teachers and you'll hear ten different experiences. Some teachers will go to local clinics, pay about 50 baht for the medical check, be in and out in ten minutes and the doctor won't even pick up a stethoscope in anger.

Others will go to a proper hospital, pay anything up to 700 baht and actually be required to give a blood sample and answer a few questions. Conclusion? It all depends where you go. But the end result - obtaining the medical certificate - is the same. Getting a medical certificate is not a big deal at all.

"The school has asked me to work a one-month probation period and then they will assist with the documents for a b visa and work permit. I am currently on a tourist visa and I am very worried that I will get into trouble. Should I have the correct visa and work permit before starting the job?"

It's certainly not unusual. Billy Weaver had the following to say on the ajarn Facebook page - In my experience, it takes many schools that long to even get the paperwork together. They dont want to give you a work permit if you prove to not be the teacher they are looking for. so it takes them time. If you have any problems then you generally have immigration or whoever call the school. That's in my experience.

I am HIV positive and have been offered a teaching job in Bangkok. I am worried my status will be an issue. I was hoping to not disclose my status to my employer and I receive medical treatment in the UK and will continue to do so even if I leave. Is this medical examination the same one for the work permit or is this something different?

We put this question out on social media and here are some of the responses.

"My medical examination includes HIV tests for a work permit"

"I was told by a doctor that it's illegal to discriminate/test for HIV here unless you have a high risk job. Could be a different story in reality though"

 "My medicals for work permits have never asked for hiv tests"   

Several teachers all remarked that the medical test only checks for syphilis.    

In conclusion, yet another one of those infamous Thai grey areas.