Regarding the succession, those who say they want William to be king and not charles are not going to have their wishes fulfilled. It just doesn't work that way. William would presumably not want it either as he knows the system well. Charles will turn out to be a reasonably good sort of king no doubt and the ones who thought William should be king will have to learn more about the system and I bet they'll be quite happy with the way things run anyway.
I think that is correct - it is really muddled thinking to be in favour or a hereditary monarchy but then want a say in who becomes King by opining that someone who isn't first in line should become monarch. You can't really have it both ways.
But I think we will see this time and time again, due to the length people live these days. Charles' problem isn't really that he is fundamentally unpopular (he was very popular in his 20s and 30s) - his problem is that he's simply been around too long - time has chipped away at his popularity (not least because of certain events) and people frankly have become bored of him as the never-quite (or not-yet) King.
But if Charles lives to the same age as his father, then William will be looking at another 28 years before he becomes King, and also plenty of time to blot his popularity copy book and similarly become the endless, never-quite (or not-yet) King. By then, of course George will be 35 and likely riding the crest of a popularity wave, perhaps newly wed with a young family himself.
So while today people want William rather than Charles - fast forward to 2048 and with Charles coming to the end of his reign and I wouldn't be at all surprised if the same people want George to become King, not William. It is simply a tendency to want someone young and fresh, not old and stale.