It varies from force to force, but the vast majority of PCSOs do have the power to use reasonable force, same as a PC/Special as per the Police Reform Act 2002
As for 'plastic plod', you obviously read tabloid newspapers. PCSOs are a valuable resource, the intelligence they gather and reassurance they provided is second to none. Modern policing isnt just about arresting people.
The "reassurance" they provide becomes 100% useless once two things happen, firstly people aren't reassured when they find out those essentially fake police officers can't do a damn thing to help them in 99% of situations you want a real cop around. Secondly, criminals know they have next to no real power so don't intimidate criminals in the slighest.
Lol, modern policing IS just about arresting people, but GOOD modern policing is about arresting the RIGHT people. This isn't modern policing, this is raising policing numbers artifically by hiring two lesser trained vastly lesser powered for the price of one more expensive trained higher waged real police officer. This is the "election" plan of policing. Make it look like we have more police and hope having more visibility lowers crime. It doesn't, it wouldn't even if they were all real cops.
New York is pretty much the ultimate model for great police work. Decades decending into terrible crime. Massive police force being mismanaged. Massive visibility, there were cops everywhere it made no difference at all. This changed when a mayor came in who wanted change, not campaign stats. He brought in the right man to manage the police and that man brought all the right idea's to the police force. Crime dropped ridiculously with the same staff(roughly) just better idea's and plans.
Hiring baby cops because they are cheap is ludicrous, not only are they less effective than the lower number of fully fledged police officers that could have been hired instead, they are now a whole bunch of people the government won't be able to fire despite the plan not working. So when finally someone decides that real money and the right person can fix the police department that person will be stuck with thousands of useless idiots taking a wage for doing basically nothing at all.
Real police work is simple, investigations, going after the bigger people, making area's harder to commit crime in, police officers on foot and on patrol in the right places at the right times. Not wasting police time arresting dozens of people infront of camera's on a friday night for being a bit drunk.
Oh well, police rant over.
Citizens arrest is basically useless these days, it has no real power and I'm sure their are legal precedents where citizens arrests have been ruled unlawful in court. Which means despite the law as writen on paper, if there is prescendent in the court for several arrests to be deemed unlawful that is what matters now, people forget its not a case of whats on paper. Paper law is essentially a guide and can be overturned in the court.
Keeping anyone for so long in a store unlawfully is simply wrong and something should be done in this case. However don't put money in those scum sucking lawyers pockets. Go and speak to a REAL lawyer. Ask them, if its a highly winnable case then you'll probably end up with MORE compensation than when you go with this no win no fee twits. People don't get, its no win, no fee, but if you win, they will take 50-80% of the money you get so you end up with vastly less money than you would paying a non chavy lawyer upfront.