We have (or at least had) two forms of security at our theater. One, which is really helpful (in theory) is a rent-a-cop and a cop. Both are there from the theater. Basically it is just to keep people in order, make sure to calm down the situations in case there is a fight or something. Problem is that most of the time the cop just sleeps in the corner. My fear is that one day there will be something big that happens and the cop, who will have slept right through it, will recommend that the theater shuts down.
The other form is cast security. Which is a waste of time and, in reality, perfectly donateable body parts. For the most part they are supposed to get people to sit down so that they don't get in the cast's way. In reality they get more in the way than the audience does.
The perfect setup would be to have a cop who enjoys RHPS to be there and provide security. Some casts are lucky to have this. Some are not. A good idea is for the cast to become friendly with a cop and have the theater pay for him to watch the place for the show. Off duty cops like this sort of thing. Problem is a) convincing the theater and b) convincing the cops.
As far as drunks we kick them out without a refund if they are too rowdy and annoying. (I've seen this done only once.) More than likely though they pass out before anything really bad happens. As far as eggs go, the cop and rent a cop search bags minimally for things like eggs, shaving cream and pre filled water guns. People fill their guns at the bathroom sinks.
You asked for info about security, so here goes:
We usually have 3 or 4 people work security because we have a theater that seats over 500. We don't have a full house unless it's Halloween or something, but it's a lot space to cover. The people working security are people affiliated with the cast but who do not generally perform.
They are considered almost as a separate entity from cast and crew. We have a head of security that was appointed several years ago and he generally delegates the responsibilities in that area. There has been some discussion of making this an elected post, but nothing has been done about that (so far).
The security people watch the audience coming in and check through bags, etc. looking for waterguns because management does not allow them. If they miss one and someone shoots it in the theater, security will collect it (it is announced during preshow that waterguns are not allowed). Other than that, security generally tries to prevent fires (open flames are allowed, but are carefully monitored after an incident where someone set fire to a roll of toilet paper) and keeps the aisles clear of people so the actors are not obstructed.
Occasionally we will have drunk people show up and they are generally ignored unless they become disruptive. Then they are escorted to the lobby and handed over to management. This doesn't happen too terribly often.
Hope this helps.