Damn man, that is terrible and depressing. Sorry, you guys had to deal with that shit on a Halloween about candy and fun. Why did the cops ignore you do you think?
Depends on the types that frequent said bar, if there are daddies there you will probably get plenty of free drink, and maybe even if not. You won't know til you try. Plus denim can be very sexy depending on what the actual outfit looks like. ;P
You're assuming you won't get free drinks at the bar. Just make sure you keep your eyes on the liquid fuel from the time it leaves the bartender's hand.