Lucky if I meet two a year and have lived here twenty four years. I understand there are more out there but not many. Happy that your friend is willing to make an effort to learn. Would you like me to make a video for YouTube proving my point? Foreigners who are fluent have asked the same their hunch less than 10% . My guess about 1% if that.
I don,t tend to go showing mine off in public. Hey look everybody I have a $$$$ for the week I think I might marry her. When I see foreigners showing off their rentals in public I can,t help but cringe.
I would not touch anything in any tourist areas PERIOD! Thankfully I can spot a working girl miles away. They are great for one thing bang and toss. Otherwise move on if you are serious.
And again not learning Thai. If you understood Thai there would be far fewer problems besides majority of bad ones will avoid you. No dodgy Thai wants a smarter than average foreigner hanging around.