Under the FAA system I can fly say a longranger after finishing my ppl in a robbo without any further training or endorsements, throw 6 pax in it and off we go
Yeah, this is true but doesn't the insurance industry in the US prevent this from happening to a certain extent, unless you're filthy rich and exorbitant insurance premiums don't matter.
I don't see why the UK insurance would be so different. Granted European society isn't as litigious as their American counterparts, but the insurance companies still love to charge plenty.