100 %! They need to be put in place. To me it wouldn´t matter if they where put out of business because of illegal drivers. They probably give a better service anyway.
No, it´s not! A car, you can rent from 9 000 - 12 000 baht per month. That would only be 300 - 400 per day. As a taxi driver you can easily make trips for 1 500 per day. Let´s say that 900 goes away including rent and gasoline. I would assume it is most India and other Asian nationalities that are doing this. They will be quite satisfied to have 600 baht or more per day.
To OP: I would say you are screwed! It your obligation to know how your visa works.
After that you say no money for pay overstay nor flight home. Only money for mini weekend with GF?????
Now it sounds like you do anything to get screwed ????
The biggest problem, would be that he will not even reach the possibility to fly, if he not pass immigration and pay the fine. Which means, you can not come to the point of leaving the decision to the airline.