Actually, it is not a good idea to COMPLETELY protect a child from bacteria. Being exposed helps to build the immune system. I am not suggesting to let a child get into anything he/she wants, but don't get paranoid about bacteria either.
It was a fun day. They also had food stalls and typical stuff for sale. They had oiled poles with money pinned to it and kids were climbing the oiled pole to get the money. I also saw 2 kids straddling a beam. They were wearing boxing gloves and punched each other until one fell of the beam. The whole thing reminded me of American county fairs.
I don't think you can be 100% sure that the family would honor the agreement. Not thinking about something doesn't guarantee it won't happen. An ostrich that buries his head in the sand is exposing himself to attack from behind.
The name of the restaurant is all in Thai, so I have no idea how that would help, but if you go down Jomtien Beach Rd. as far as you can go you will run right into it. It is the very last restaurant there.