There should be regular re-tests every 3-5 years in order to keep the license, just a cut-down practical test. But, fail and you're back to a provisional license and having to do the full test again, theory and practical.
I've often thought that would be a good thing for all drivers. In my Utopian paradise, drivers would be encouraged to develop their skills with training, IAM-style observed runs, etc, along with regular tests. People who didn't want to do training could carry on driving, but with various restrictions on what they could drive, etc. People who did might enjoy discounts on insurance, I dunno, reduced road tax, etc.
It's a bit weird, when you think about it. We take people through a very basic training and not very many hours of driving, all with an instructor, then we get them to take a test and say "off you go." It's a bit like finishing medical school and suddenly finding yourself in an operating theatre doing surgery. Pass Plus is a nice idea, but I think it should be integrated into a general "driver skills improvement" approach, with a combination of mandatory and voluntary aspects to it.
I'd probably ban fewer people, too. Sure, for deliberate (subject to the differences in what some of us consider "deliberate") offending, like drink driving, a ban's perfectly in order. But I don't like the "totting up" ban - it seems unhelpful to address someone's routinely substandard driving by depriving them of the opportunity TO drive. I reckon a totting up ban should involve a regular attendance at naughty driver school, where you're trained and tested to show you've improved. And if you haven't, then out with the banhammer.