Now I see it's an RC that's picking this fight. Hmmm.
Rocks being very common in that part of the world, the Grecianized Jews had many names for rocks and metaphoric use of them in scripture. Such terms as stone (lithos), little rock (petros), boulder (petra), or foundation (themelios). In any case it is clear in the writings of both the Apostle Paul and the Apostle Peter that Jesus Christ is the corner stone / foundation for the Church:
1 Corinthians 3:11 For other foundation can no man lay than that is laid, which is Jesus Christ.
1 Peter 2:6 Wherefore also it is contained in the scripture, Behold, I lay in Sion a chief corner stone, elect, precious: and he that believeth on him shall not be confounded. 7 Unto you therefore which believe he is precious: but unto them which be disobedient, the stone which the builders disallowed, the same is made the head of the corner, 8 And a stone of stumbling, and a rock of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed.
And Peter's name change? It had to do with his answer in Matthew 16 about Jesus. We all must believe what Peter said in order to be saved:
Matthew 16:16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God. 17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. 18 And I say also unto thee, That thou art Peter (petros), and upon this rock (petra) I will build my church; and the gates of hell shall not prevail against it.
John 3:16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
1 Peter 2:3 If so be ye have tasted that the Lord is gracious.
4 To whom coming, as unto a living stone, disallowed indeed of men, but chosen of God, and precious, 5 Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ.
So the debate need not rage on. The Bible already answers the age old point about Peter being the foundation of the Church. He isn't, Jesus is. Even Peter wrote that Jesus is the corner stone / foundation. Jesus is the rock on which he builds his Church.