As for Charles, he will do fine.
Alas I am a monarchist and seeing what other countries have as an alternative system, I think we are just fine IMHO.
As a young man I felt a bit sorry for him. Although they had met before either was married, many think Camilla wasn't considered suitable. I suspect Diana was chosen for him, not a good start for a close relationship.
As for the republicans, they talk much about the cost of royalty without any consideration of the costs involved in the hustings and election of a head of state.