Mormons, like Catholics, believe in apostolic authority. We believe, however, that in the scripture you cited, revelation is the rock upon which the Church is built, not Peter. Peter, however, knew by revelation that Jesus is the Christ. Mormons believe in Peter’s apostolic authority, but we believe that authority was not passed on upon the death of the apostles and had to be restored in modern times in preparation for the Second Coming of Christ. Joseph Smith was a man, valiant in his testimony of Christ, who received revelation and visitations in order to restore the lost authority that Peter had. Mormons do not believe in the “trinity,” a definition of the godhead that was codified hundreds of years after Christ’s birth, but both of your statements are true. Jesus Christ is and was “God the Son,” because all three members of the Godhead, though separate beings, are together God; but Christ is also the Son of God. Mormons believe that God the Father and God the Son are glorious, perfect, all-knowing, all-powerful resurrected men of flesh and bone; the Holy Ghost is a personage of spirit who can dwell within us. Mormons are enjoying a time of fruitful partnership with Catholics in upholding the eternal morality God has established through prophets and scripture.

Yes. Shortly after Mormons were forced to migrate to Utah Territory to escape persecution, their crops were overcome by a plague of crickets, which threatened them with starvation. Miraculously, seagulls poured into the area, filled themselves with crickets, disgorged them, then ate even more, until the threat was over. There is a monument to the seagulls in downtown Salt Lake City.