PCSO can't do either - think of them as civilian police officers - they can follow you down the street whilst calling for a real police officer on their radio

If they grab hold of you you're not supposed to resist - but it's a grey area - they're not supposed to do it, and I'd likely break their hold and walk away

Think of PCSO's as "ticketers" - they see you do something and ask for your details and issue you with a ticket