FWIW,
The worst behavior I've ever seen is at Giants stadium. I saw several individual people so drunk they needed to have their stomachs pumped and were in grave danger of vomiting on innocent passers by. Why two guys need to share a stall in the restroom is a question I don't want to think the answer to. Still, that's probably about .5% of all the people in attendence at that game. I'm able to make the distinction between a very small minority and the overwhelming majority.
I've been to probably close to 200 games at the Vet, LFF, Citizens, Franklin Field, etc. and I've never felt uncomfortable or threatend. I have seen some fights in my time and boorish behavior, but it's always been on drunken jerk off beating up another drunken jerk off. A normal person has nothing to worry about.