I tried to get on a plane from bkk to Vietnam and I didn't have a visa, they wouldn't let me on the plane, this was in October of Last year and I had a US passport.
So I went to Cambodia where I got a visa at the airport.
Vietnam you need an e visa I'm pretty sure. Takes about 3 to 5 working days if you fill it out correctly.
They teach English in the thai schools but a lot of younger kids don't want to learn it.
I myself am trying to learn thai, it's hard and embarrassing at times but I feel if I'm in another person's country I will show some respect to their culture and language and not try to force mine down their throat and as far as misconceptions about Americans trying to change things, that's the American government for the most part, not the people.
Most Americans I know believe live and let live and leave me the hell alone.