You are being illogical. You cannot agree that the Bible claims, as it does, that God is the only Rock forever and then claim the Bible also calls Peter the rock. First of all, as already shown, Peter was named Peter BEFORE his statement of faith in Christ. Secondly, regardless of the language Jesus spoke, the translations (which I'm sure you will claim are the result of the Roman Catholic translators!) all use a different word for the rock "Cephas" or "Petros" which is Peter and the feminine form Petra, which Jesus says will be what the church is built on. When you add to this that Jesus Christ is the chief cornerstone, which are words Peter himself wrote, you have no contradiction in the Bible at all, but simply that Jesus is the Rock and it is faith in this Rock, as shown by Peter's statement, which is what the church will be built upon. As has already been shown here, it is the faith of the apostles in particular which is the foundation of the true church -- which is spiritual and not physical.
You referenced Isaiah 51:1: "Listen to me, you who pursue justice, who seek the LORD; Look to the rock from which you were hewn, to the quarry from which you were digged;"
The interesting thing is that that translation is not in accord with the modern Hebrew text itself. Here is the word for word of the text:
"Hear me pursuers of righteousness and seekers of Jehovah. Look to the rock from which you were cut, and to the hollow of the pit from which you were dug. Look to Abraham your father and to Sarah who bore you..."
This is a LIST.
Even more interesting is the Alexandrian Septuagint, which was translated by the Hebrew Scholars themselves from the ancient original paleo Hebrew to Classical Greek several hundred years before Christ. Here is that translation, and there is a very interesting difference:
"Hearken to me, you that follow after righteousness and seek the Lord: Look to the solid rock which you have hewn and to the hole of the pit which you have dug...."
As interesting as these differences are, neither suggests the rock being spoken of is Abraham.
Which is not surprising since God had already stated through Isaiah that He knew of no other God and no other Rock but Himself (44:8 )
In the meantime, I totally miss Peter's authority and leadership among the Apostles! I see where Paul rebuked him publicly, however! And I see where Peter identifies himself as both a servant and apostle in introducing his two letters. But I do not read of him either claiming to be a leader of the Apostles or being treated like one by them. In fact, in Acts 15, at the Great Council in Jerusalem, you find that it was James (the half-brother of Jesus Christ) who was the leader or chairman of the meeting. Each person gave their accounts and it is James in Acts 15:13 who sums up and gives the answer.
"And after they had become silent James answered, saying 'Men and brethren, listen to me. Simon [note: NOT Peter] has declared how God at the first visited the Gentiles to take out of them a people for His name, and with this the words of the prophets agree...therefore I judge that we should not trouble those from among the Gentiles who are turning to God..."
In other words, it was James who was the leader of the church there, not Peter, and he did not even refer to Peter as Peter, but as Simon!