"But he turned and said to Peter, Get behind me, Satan! You are a hindrance to me. For you are not setting your mind on the things of God, but on the things of man.
Rock? Yeah...a hindrance (stumbling block), not to mention when he denied the Lord three times!
So, yes... God did appoint a leader. His only begotten son. Jesus.
As for the keys? Metaphor for the apostolic authority given to ALL of the Apostles as they were to spread the gospel.
Hoss
In the spiritual,yes.
What you say is true, but incomplete. And that is the position in which all non-Catholics find themselves - searching for completeness. The veracity of my claim is found in the myriad congregations of evangelicals and protestants. None can stake a claim on the Truth. Most hold the belief in ‘sola scriptura’, even tho that belief is nowhere to be found in the Bible; the Bible that was compiled by the Catholic Church in first couple of centuries following Jesus’ resurrection and ascension. But surely you are already aware of that.