I think a lot of people question Camilla's denomination of faith because she married a Roman Catholic.
To be honest, I think the whole discriminatory view of the Act of Succession was something that was instigated and written in stone (well... ok... on paper) because after Henry VIII divorced himself and his country from Rome, there was a lot of religious politics that came into play and it was to assure that the succession would always remain with the Church of England. It was just how things are and continued. Personally, I'm happy to see that the discrimination against marrying a Roman Catholic has been abolished. I also understand and agree with the codicil that any monarch must be in communion with the Church of England. Roman Catholicism is the only denomination of faith the Act of Succession was adamant about. Politics, politics, politics.
When we really look into the Roman Catholic church and the Protestant denominations, its the same God. Its the same prayers and the same hymns with very little differences other than only one recognizes the authority of the Pope in Rome. My hubby's family is Presbyterian (Dad-in-law was a minister) and I was raised Roman Catholic. Attending my first Presbyterian service, I fit right in and felt comfortable with it.