“Finally, the Scriptures that we both hold so dear are the ones the Catholic Church’s leaders deemed divinely inspired. The formal Catholic Church selected which writings were to be included in the New Testament and which weren’t divinely inspired.”
No. The Councils in Africa ratified what was already the common acceptance of scripture, and had been for 200-300 years. It was the local congregations that decided which writings were on par with the already existing scriptures, which were important in preventing false doctrine from the day of Jesus’s resurrection.
Even JESUS, raised from the dead, used scripture to instruct:
“24 Some of those who were with us went to the tomb and found it just as the women had said, but him they did not see.” 25 And he said to them, “O foolish ones, and slow of heart to believe all that the prophets have spoken! 26 Was it not necessary that the Christ should suffer these things and enter into his glory?” 27 And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself...”Did not our hearts burn within us while he talked to us on the road, while he opened to us the Scriptures?”” - Luke 24
And Paul used it to evangelize the Jews:
“11 Now these Jews were more noble than those in Thessalonica; they received the word with all eagerness, examining the Scriptures daily to see if these things were so. 12 Many of them therefore believed...” - Acts 17
Christ used the Old Testament scriptures to instruct them on all the prophesies concerning the Messiah. Paul, likewise, is referring to the Old Testament and using it to help people realize Christ was the fulfillment of the Old Testament scriptures regarding the Messiah. The Catholic Church selected and protected the New Testament scriptures. Local congregations did not decide what was to be included in the New Testament. The successors of Peter and the hierarchy of the Church decided that.
No one is denying that Christ used Old Testament scripture to help people recognize Him, but He relied much more on oral teaching. Anything relating to Him and how He wanted us to live in the future was taught using oral instruction, and doing miraculous acts... also known as outward signs. Our sacraments are outward signs, instituted by Christ, to give grace.
Christ loved Scripture and revered it. But He explained what it meant in a new way... He said many things to the people and the Apostles that weren’t in Old Testament scripture (for example that He wanted His followers to “gnaw” on His flesh to have life within them) and He set up the tradition of oral teaching.