Now these things, brethren, I have figuratively applied to myself and Apollos for your sakes, so that in us you may learn not to exceed what is written, so that no one of you will become arrogant in behalf of one against the other. 1 Corinthians 4:6
we also see that in the he New Testament writers constantly appealed to the scriptures as their base of authority in declaring what was and was not true biblical teaching…
I think it is overreaching, to say, this means only scripture has the highest authority. St. Paul often appeals to the OT, to show, rightly, that what he is preaching about Jesus is found in the OT (what is written). That Jesus Himself, fulfills the prophets and the law.
However, what St. Paul is preaching, the Gospel, is only being written as he is writing his letters. You would have to claim, then, that St. Paul does not include what he is preaching, the Gospel, as having any authority beyond the OT. (The OT is what St. Paul is referring to anytime he writes “scripture”.)
The note on 1 Corinthians 4:6, in the NABRE: “It probably means that the Corinthians should avoid the false wisdom of vain speculation, contenting themselves with Paul’s proclamation of the cross, which is the fulfillment of God’s promises in the Old Testament (what is written).“
Claiming that St. Paul is teaching that scripture has the highest authority, is an incomplete understanding of what is taught in the NT. Later, we find that St. Paul’s writings are being called “other scriptures”.
And consider the patience of our Lord as salvation, as our beloved brother Paul, according to the wisdom given to him, also wrote to you, speaking of these things as he does in all his letters. In them there are some things hard to understand that the ignorant and unstable distort to their own destruction, just as they do
the other scriptures. 2Peter 3:15-16
So, this is an example of what we call Tradition, being elevated to the status to which St. Paul held the OT.
The RCC has not changed on this position.
Again, look to the liturgy. Where is Christ explicitly present? In the Eucharist, of course. In the gathering of baptized, who are the Body of Christ (the Church), and in the Liturgy of the Word (scripture).
The Body of Christ (the Church) is as Jesus is. Fully divine and fully human. The human aspect (us) is imperfect, makes mistakes and sins. The divine, Jesus Himself, is perfect and sinless. We Catholics must walk a balanced path. Never believing that we ourselves are sinless, free from mistakes, and never denying that we are freed from sin and made perfect, in Christ.
This should be our view of the Church, itself.
I recommend that you read Dei Verbum.
Pax tecum.