The thing is - you can't make honking less loud without making loud honking illegal.
And with the billion annoying examples such as permanent honking in the traffic, yelling around the markets, backward social attitudes, low personal hygiene, and similar staff often (but not always) found in certain groups, you realize that you can't really make regulations on all that, and even if you did, the police officers would simply lack the time to control and sanction all of those widely spread minor "offenses".
Which leads us (or at least me) to a conclusion that immigration should be very selective in the first place, as it's almost impossible to throw out the annoying but not quite criminal people later.
Great points. I think that the reasons behind the bottom line problems you described are:
OK, this makes me feel depressed and helpless. :D