For example here in Finland (one of the strongest passports) the embassy informs the flight has to be straight from Finland to Thailand or the ticket has to show the route from Finland. So I guess the airline thinks you mighn't allowed to enter.
I'd say most people don't speak basic English, not even in Bangkok.
It's very good to know some basic Thai phrases. Thais usually appreciate that and then it's easier to find a way to communicate. Google Translator helps, as said before.
Yesterday SCB didn't accept my education visa. Kasikorn accepted but asked me to bring the letter from the school. I had also the document of my address from immigration, and with those documents they opened an account. This was in Hua Hin.