“And do most people know who the rightful successor to Christ and the apostles is?”
Are you trying to say their are successors who will propitiate the sins of the world? Or who will write new scripture, add to the Bible? Or present additional Gospel or doctrine?
Roman Catholicism has already done this along with the Mormons.
At the Council of Trent, the Roman Catholic Church official proclaimed their man made derived "Sacred Tradition" to be equal to inspired Scripture.
What those "Traditions" are the Roman Catholic cannot tell us.
http://www.thecounciloftrent.com/ch4.htm