The pool hall is the one that is has the store front type look to it. IF you were to build a fence, it would have to be on the skating rink's property, and as they are looking to sell, I really doubt they are going to spend the money to build one. And having another business spend the money to build a fence on another's property isn't logical.
As for the rest, you are assuming that all pool players are like the one idiot that lived next door to you. That is the exception, not the rule. Besides, you said he was playing at BARS, not pool halls. When you play at a bar, there is more chance that the people hang out after league to socialize and drink (that's what people do at bars). THIS is a POOL HALL. The purpose is to play pool, which is really hard to do if you are stumbling drunk.
Also, bars' main business is alcohol, therefore alot of them don't cut people off when they probably should. This main purpose here would be to play pool, and drunk idiots have a way of pissin' off the other players, so I doubt the owner will hesitate on cutting people off when needed. When you stop the problems before they begin, you don't need security.
Like I said before, and I'll say again. There is a BIG difference between a pool hall that also serves alcohol and a bar that has a pool table. Please stop confusing the two.