Re: Meaning of 'thanks to' in the sentence?
No, I don't agree that using the phrase "thanks to" means they should the students should say "thank you" or be grateful. (Perhaps they should be, but that's not what "thanks to" means.)
It simply means that whatever you're talking about made something possible. Thanks to a good tailwind, the delayed flight made up the time in the air and still arrived on time.
However, I quite agree they are called "crossing guards" here. What is the term in the UK, Australia or elsewhere?
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.