Queen Elizabeth II cannot "make" Charles do anything. As monarch, she has to approve the marriage of the heir to the throne, and she approved both of Prince Charles' marriages. If Charles had married without his mother's approval, the marriage would not have been valid in English Law (although it might have been in Scotland - that could have proved interesting).
Prince Charles is heir apparent to the throne and will automatically become King when his mother dies or abdicates, whether he is married to Camilla or not. His present titles are Prince of Wales, Duke of Cornwall and Duke of Rothsay and none of these are compromised by his present marriage. Where we go into uncharted waters is that on becoming King, he will be Supreme Ruler of the Church of England, while married to a divorced woman whose previous husband is still alive. However, the Church of England tends to be quite accommodating.
No.The marriage is doing well. The couple are well suited. The Queen gave Charles permission to marry and the marriage was blessed by the Anglican Church. Charles' title is not endangered. Charles would not have married Camilla of it meant being taken out of line of succession. They would have remained partners.
No. they are obviously very happy together, and anyway it is most unlikely that they would get divorced to please me. if I could not stop them getting married (assuming i wanted to) how could i make them divorce?