You very clearly state that Kephas/ Cephas is massive rock. Yet you ignore that Jesus being a local Jewish boy probaly spoke Aramaic, and the proof would be that Paul Referred to Peter the same way on a number of occasions.
Gal 2:9 and when they perceived the grace that was given unto me, James and Cephas and John, they who were reputed to be pillars, gave to me and Barnabas the right hands of fellowship, that we should go unto the Gentiles, and they unto the circumcision;
Gal 2:11 But when Cephas came to Antioch, I resisted him to the face, because he stood condemned.
1Co 1:12 Now this I mean, that each one of you saith, I am of Paul; and I of Apollos: and I of Cephas; and I of Christ.
1Co 3:22 whether Paul, or Apollos, or Cephas, or the world, or life, or death, or things present, or things to come; all are yours;
1Co 9:5 Have we no right to lead about a wife that is a believer, even as the rest of the apostles, and the brethren of the Lord, and Cephas?
1Co 15:5 and that he appeared to Cephas; then to the twelve;
“Gal 2:11 But when Cephas came to Antioch, I resisted him to the face, because he stood condemned.”
It’s worth noting that if Peter really was the Chief Cornerstone instead of Christ, that he certainly was never treated that way. Paul’s public rebuke of Peter is a good example of this. James’ presiding over the first church council and declaration of the judgment is another. Nowhere in scripture do any of the Apostles give any indication that they are anything but equal with one another. Paul himself didn’t even meet with Peter or any of the Apostles at all at first, but went straight to work in his ministry:
Gal 1:15-17 But when it pleased God, who separated me from my mother’s womb, and called me by his grace, (16) To reveal his Son in me, that I might preach him among the heathen; immediately I conferred not with flesh and blood: (17) Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
The only teaching along the theme of “rocks” that we do see is Peter’s discourse, wherein he calls all Christians “lively stones” building up a holy house with Christ as the Chief cornerstone. It’s no coincidence that Peter uses an analogy that has stones being built upon the stone of Christ, since that is the lesson Christ gave to Peter in the beginning.