you just have to remember that Thais are soooo jealous ...and will inform the Police if they think you are working.
You can obviously get a Teaching job and get the correct Visa ...but when I asked my Village school if they would get me the visa they said " oh no problem...you can work in the Village no problem"
Don't do it ...I was asked.to teach English in my Village school...asked by the area education boss....but his best friend was the Police chief ...who kindly advised me that I would be arrested and deported ....
being Married has no bearing on the Visa ...as it states for the UK ...she can be just your girlfriend...spouse or civil partner .
You should always start with a 6 month visitor visa ..maybe do that twice ...most importantly is you show she has a reason to go back to Thailand...ie good job...house ...children ...get a letter from her employer stating how.long she worked there .
Don't transfer any more money...you need to show you UK balance ...she doesn't need any money as you are her sponsor .
Paul King is someone that I trust .
But I've done 3 visitors visa....2 visa for 2.5 years and the life in the UK for my wife so she now has ILR and next is a British passport ....it all takes time ...and you need to give MORE INFO THAN THEY ASK FOR ...
BUT...the most important thing is ...your bank balance and a strong reason why she will return to Thailand