Now, as to what to do with people that you've apprehended, and similar matters.
A while back, I posted a video elsewhere depicting a fight between a PO, two civilians assisting him, and three very inebriated gentlemen trying to gain access to a bar. Someone with experience of working doors in Britain suggested that the best thing to do would be to shove them away, get inside the establishment, lock the door, and let the three drunkards become someone else's problems.
Thing is, it is not legal for a PO to do so. Remember what I said about the state making it their business as to how and when you decide to get sloshed? Here's how it works:
Policemen, as well as PO's, have the right - and usually, the legal obligation - to utilize what's known as the Preventive Detention of Inebriated (I'm going to be using PDI for short) Act. Basically, this means that a person who is drunk or intoxicated to the point of posing a danger to himself or others, may be taken into temporary custody. If done by PO's, this means that he is to be handed over to the police as soon as possible. As is the case with disrupting public order, public drunkenness is not a crime per se. The law is intended to be a nurturing one, and probably owes some of it's existence to the days when workers received half or more of their payment in alcohol. As with regular detainment, this can also quite easily turn into an apprehension, should the person being intervened against offer up violent resistance or carry drugs and/or weapons on his person.
Under local law, it is not legal for a person to be "noticeably drunk" in an establishment or in the subway system - however, "noticeably drunk" is not synonymous with "posing a danger to him/herself or others". Since using alcohol testers is illegal for PO's (it actually counts as the legal equivalent of a body cavity search), pretty much all they have to rely on is their judgement. As such, being turned away from an establishment for being too drunk is highly possible even if you haven't had anything to drink (which admittedly is also possible pretty much everywhere else in the world).
However, ordering a person to leave an area is, for a PO, technically part of your professional conduct. As is detaining people, as well as your duty to report every crime you become aware of while on duty to the police. The reinforced legal protection of type 1 guards is technically what might be called an amendment - we have the legal status of public servants, but we are not public servants in the strict sense of the word. PO's, however, technically represent the state - whilst at the same time usually being paid by private interests. As you might understand, this is grounds for a conflict of interest.
PO's are required by law to report everything the see or hear about to the police, but doing so, I'm sad to say, may quite possibly cause more problems than it solves. If the Licensing Authority were to continuously receive reports of every threat, every person removed, every barroom scuffle, every drug use and every stolen object at an establishment, it's quite possible that they deem the place to rowdy and decide to withdraw it's permission to serve alcohol, forcing the place to close down and leaving the PO's as well as a whole lot of other people without a job.
Adding to this is the fact that becoming a PO requires a virtually clean criminal slate (there are exceptions, and I'll get to them later). Not only do you need a thorough lack of convictions, but you also need to be considered a relatively upstanding citizen. Having known contacts with organized crime figures or outlaw biker gangs, for instance, is usually grounds for an application being denied, as is having been detained under the PDI act a large number of times. The problem with this is, again, that it may create more problems than it solves.
A newly appointed PO in his early 20's with a clean middle-class background, quite frankly hasn't usually got a clue as to which people's bark are worse than their bite, and which ones are liable to start conflicts that continue long after the shift is over. In order to solve this, bars and clubs have a tradition of hiring "hosts" who, while not always hardcore criminals themselves, have pretty good glimpses into the criminal underworld. Basically, they're there because they know which people they can turn down without consequences, and which ones they can't. I've personally seen these guys hold back PO's preventing them from entering into fights with unsavory characters. Granted, this problem is decreasing in scope, chiefly due to the fact that more and more guards and PO's are being recruited from the same neighborhoods as the gangsters and know how to talk their talk, but the fact remains that you've got what is technically government representatives working side by side with thugs. The problem is still on a small enough scale that you can head into a bar or restaurant just thinking that their food and drinks taste nice, without knowing anything about Hells Angels, Bandidos, Satudarah, The Brotherhood, Chosen Ones or anything similar.