OK there are two things that you guys go back and fort between
(1) Functional use of english - clearly beneficial for the person, this is market driven (if they don't speak the predominant language they are at disadvantage, in Miami that would be spanish). Note that the FAA example falls here - it is a job requirement, just as being a licensed pilot.
(2) What the title of this thread implies - a government (local or federal) requirement. The arguments here have nothing to do with the market. Let's consider one of them - to make the nation cohesive - would you also prefer all laws to be federal - that's along the same venue?

The truck driver regulation falls in the first category - part of the job is to be able to effectively communicate with the police. Now, if you think that every single person should be required to do so, not just drivers, well I would argue that English is not enough, there is a communications skills component. I can imagine that the obvious and worst possible solution is to administer a test and whoever fails it would be taken away from the society.

In any case certainly one can distinguish between citizens and non citizens, the former having a free pass just because they happened to be born here, but viewed objectively, I don't see a non-political reason for such distinction. Couly gave a good example how noncitizens are being screwed for what I see as no good reason.

And yes, I'm immigrant, I learned English (as well as several other languages) and I am not sure how long I would like to be in US. Which obviously doesn't preclude me from expressing my opinion in better than passable english .