Not to the same extent as a casino. Maybe "bar" means something else in America, in Germany it's just a place people go to have a drink after work (like "Cheers"). It's not expected to get shitface drunk in them and they are legally obliged to keep quiet outside after 10pm.
You are telling me that these junkies are never violent and there is never fights? As such crime. Or they(bars) don't get robbed or gather loud undesirable people?
Not the same as a casino or brothel. And if it's the kind of bar that does it would get as many complaints (as soon as they make noise after 10PM they'd start getting people calling the police on them). All the bars I know in my neighborhood don't get the kind of trouble you describe (at least not often enough that I ever noticed it).
But it may also be a cultural difference between Germany/Austria and US/UK - bars/pubs are just not that troublesome here.
I don't think that's true, or that it really matters. There's plenty of brothels in Tokyo and crime is as low as it gets.
But even if it did, why should we use zoning to determine where crime is allowed to happen and where it isn't? Address the problem, don't just push it off somewhere else.