This is only your interpretation of Scripture, one that I find laughable. Speaking in Aramaic Jesus would have said "You are Kepha (rock), and on this kepha (rock) …" The supposed dichotomy between Petros and petra is supported neither by the context nor by philology.
But again, let us not get sidetracked by a discussion of which is the correct interpretation. You have one interpretation and I have another. Both claim to be based on Scripture. Without an divinely established authority to which we can appeal we are left with nothing but private opinion. Nor will it do to appeal to the Bible; that is where we started and is the source of our disagreement.
If we look at the history of the Church we will find that it always claimed the authority do rule on disputes of theology. Indeed it was this authority which ruled on what is the true canon of Scripture in the first place.
Oh it will do for me.
Psalm 18:31, "And who is a rock, except our God."
Isaiah 44:8, "Is there any God besides Me, or is there any other Rock? I know of none."
Rom. 9:33, "Behold, I lay in Zion a stone of stumbling and a rock of offense, and he who believes in Him will not be disappointed."
1 Cor. 3:11, "For no man can lay a foundation other than the one which is laid, which is Jesus Christ,"
God said it, I believe it, that settles it.
>> Indeed it was this authority which ruled on what is the true canon of Scripture in the first place.<<
That is so old, tired and weak. God can use anyone for His purposes. Just because God uses a person or an organization means nothing as it relates to being true to Him. I would point to Judas, or any of the nations who came against Israel. It’s even stated in Revelation that God will “put a hook” in their jaw to bring them against Israel. Even if the RCC did “codify” what was already considered scripture long before there was an RCC it surely doesn’t mean they are true to His teachings.