Peter preached the first sermon to the Jews, the Samaritans, and the gentiles as represented by Cornelius. Other than whats recorded in Acts Peter was not accepted as the foundation since Scripture teaches Jesus built His church on the foundation of the apostles and the prophets.
I can find Protestant theologians and well respected commentators who totally disagree with your "experts". Shall we play pick your "expert"? I can also find Bishops of Rome in your list of Popes who thought and said that the concept of the Bishop of Rome being the head of Christ's Church is stupid and ludicrous.
The NT was written in Greek with an occasional use of an Aramaic name. Catholics appeal to the fact Jesus and his disciples spoke Arimaic. What was Jesus' Aramaic name?
Alfred K Persson is not a theologian but he is a man after the truth. Read his article, which is documented and not just opinons expressed by academics about the name Peter at the time of Christ.