Living without a p-number is terrible but once you have it the bureaucracy here is extremely streamlined. I've lived here for four years and besides the first six months I have never had to go into a public agency to get things done. Everything is online and interconnected via the p-number. I was reminded how streamlined it was when I was trying to renew my American drivers licence online. I had to make a custom account for the DMV, which didn't work because the website was made 30 years ago. It took me over an hour to get an account and over an hour on hold to call them to ask them about my situation. Since they couldn't verify my identity I had to go through a list of the last 5 address I have had before they could confirm that the licence got sent to the wrong address. None of that would happen here.

They won't understand, because their English command (and most everyone else's in a non-higher education background) is appalling!

This isn't my experience at all.

then they'd also learn to be polite

Politeness is very culturally driven when living abroad you should learn the cultural rules rather than imposing your own from where you came from. Otherwise you'll be miserable in thinking that everyone is rude. I've had other Americans complain to me that the serving staff was rude because they don't worship the customer here like they do in the US.