As to the state of pilot training in the UK I would rate it no better or worse than in North America, Australia, NZ & Northern Europe, all these country's have almost identical accident rates with the UK having weather that is less predictable than most.
I am not sure that follows directly, because there is risk compensation.
If someone is badly trained, but still has a brain (and you definitely do have to have a brain to pass the PPL exams nowadays) they will avoid doing more complicated trips. Most people are smart enough to know their limits. Confidence plays a very big part in flying and if you don't have it, you don't do the flight (usually).
My experience of FAA training (both PPL and CPL, as well as the IR) is that it is a lot more rigorous than over here, with emphasis on aircraft control, unusual attitudes, soft field / short field takeoff techniques in the PPL, etc. A US trained PPL can fly all over the USA (facilitated admittedly by their uniform airspace etc structure). A UK trained PPL knows how to fly Goodwood to Bembridge; Le Touquet is a major adventure which needs emotional support from pilot forums
The Americans also don't fly massive circuits. Some of the circuits at the UK coastal airfields are almost into French airspace, and the last one I saw had an instructor aboard
