I don't think the age should be increased, (I too grew up rurally with no public transport,) but I do see an argument for probationary licences, with restrictions on passengers etc.
I see the argument for motorway lessons, but as has been pointed out, not everywhere is close to a motorway. Motorways are actually one of the safest road types to drive on (and i say that having earlier today, driven on one in torrential rain where not everyone thought to put their lights on, and they could barely be seen in all the spray,) but it can take while to to adjust to the speed.
I can also see an argument for rural lessons, particularly of the type of high-banked narrow winding lanes like you get in the south west. If you can't reverse back into a passing place, you are not a competent driver. But plenty of drivers don't live near roads of that sort, either. I have been quite annoyed by drivers in pristine 4x4s on narrow roads who won't pull over at all, despite being in a car more suited to off-road driving than my little Corsa.