Not really , it would be impossible to get a work visa and a huge risk doing it without . Just needs one disgruntled person to report it and you are in serious trouble .
Definately require a work permit , which they would not give you as not a preferred occupation for foreigners as a Thai could do that job . Also I would strongly advise not to even consider a volunteer visa , as it will create problems down the road when you apply for other types of visas . I you decide to help out there anyway and get caught it would mean deportation and a ban . This is Thailand I'm afraid .
An American License holder does not require to take a practical Driving test , just a colour blind test and a reaction test after watching a video . You need the form , certificate of residence from immigration and a simple medical cert from any doctor in a street clinic for around 100 baht . You will need to make an appointment at the test center you use . You will recieve a 2 year license , then after 2 years a 5 year one . This is what I did for mine in Pattaya , other areas could possibly be different .
The police checks are the least thing to worry about , think what would happen if you were in an accident and someone was hurt or worse 🤔 your insurance would be invalid .