I don't understand why many people go on about the Queen retiring and letting Charles take over as King. Is it not a long standing tradition that all monarchs rule until the pass away and are then succeeded by their eldest offspring?
The only reason Charles could take over while the Queen was still alive would be on health grounds as when George IV became regent when George III was too ill to reign. I cannot see the Queen actually retiring to let Charles take over. As far as is known, she is pretty fit and going by her mother still has some years left. Why should the throne bypass Charles in favour of William? Victoria's son was 60 when he came to the throne.