what with language being needed in order to communicate
But it isn't! Point at a pump and see what you convey - it'll probably communicate far more than your desire for a pint. You'll be told where to shove your dire attitude, the barman will go home and tell their boyfriend they had ANOTHER self important wetwipe in the bar etc etc. All of this communicates far more than "May I have a pint please", which is instantly forgettable.
Saying that, go to another bar and they might throw you out for saying please or not wearing the right kind of hat.
It depends on so many factors, a bit like cycling two abreast on a single lane road. I like that you've drawn the line at 'anything without a please isn't cricket', that's good.
In my mind, it's all proper use of language - it's just all the other stuff you may be telling other people through your choice of words that's important, and what this thread is about.
Plus I'm soft in the head.
although it does display a shocking lack of discrimination or taste when it comes to choice of refreshment.