The only way to get the correct rules and proceedure to open a business in Thailand is to apply to your nearest Thailand Embassy in your own country, not Google or on a web site.
Just go on the Thai Embassey website in the country where you live, if you cant understand English have somebody with you who can understand English and can tell you the Thai Embassy rules.
Its life here mate, why do everyone who comes here expect it to be the same as their own countries ? Certain things are much better, the weather, the cost of living and NO illegal immigrants, illegals here are ejected immediately, and to live here you have to prove you have funds to support yourself.
The girls have children so there is someone to take care when they get older, there is no social security here, not many girls with children actual ever went through a marriage ceremony, it does not mean anything here the Thai blokes just piss off whenever they find another girl.
If you get a Nationwide Plus account this costs £13 per month but there is travel insurance included, but you pay a premium for long stay?age, and certain medical conditions, but i can assure you when you add it all up.its the best deal going, certainly if you are over 65 years of age and costs nothing like what you were quoted,
The 60 days is given as visa exempt you will just be stamped in for 60 days at airport immigration, to get the 30 day extension go to your nearest immigration office fill the form in and pay 1900baht its that easy !