From the Catechism:
If He expressed Himself completely in Scripture, then it is all there. There is therefore nothing in the Tradition which cannot be found in Scripture.
I’ll answer the rest later. Good night.
From Scripture Catholic:
Thess.1:5 – our gospel came to you not only in word, but in the power of the Holy Spirit. Paul is referring to the oral tradition which the Thessalonians had previously received. There is never any instruction to abandon these previous teachings; to the contrary, they are to be followed as the word of God.
1 Thess. 4:2 – Paul again refers the Thessalonians to the instructions they already had received, which is the oral apostolic tradition.
2 Thess. 2:5 – Paul yet again refers the Thessalonians to the previous teachings they received from Paul when he taught them orally. These oral teachings are no less significant than the written teachings.
2 Thess. 2:15 - Paul clearly commands us in this verse to obey oral apostolic tradition. He says stand firm and hold to the traditions which you were taught, either by word of mouth or letter. This verse proves that for apostolic authority, oral and written communications are on par with each other. Protestants must find a verse that voids this commandment to obey oral tradition elsewhere in the Bible, or they are not abiding by the teachings of Scripture.
2 Thess. 2:15 - in fact, it was this apostolic tradition that allowed the Church to select the Bible canon (apostolicity was determined from tradition). Since all the apostles were deceased at the time the canon was decided, the Church had to rely on the apostolic tradition of their successors. Hence, the Bible is an apostolic tradition of the Catholic Church. This also proves that oral tradition did not cease with the death of the last apostle. Other examples of apostolic tradition include the teachings on the Blessed Trinity, the hypostatic union (Jesus had a divine and human nature in one person), the filioque (that the Spirit proceeds from the Father and the Son), the assumption of Mary, and knowing that the Gospel of Matthew was written by Matthew.
2 Thess. 3:6 - Paul again commands the faithful to live in accord with the tradition that they received from the apostles.
2 Thess. 3:7 - Paul tells them they already know how to imitate the elders. He is referring them to the tradition they have learned by his oral preaching and example.
1 Tim. 6:20 - guard what has been “entrusted” to you. The word “entrusted” is “paratheke” which means a “deposit.” Oral tradition is part of what the Church has always called the Deposit of Faith.
2 Tim. 2:2 - Paul says what you have heard from me entrust to faithful men who will be able to teach others also. This is “tradition,” or the handing on of apostolic teaching.
2 Tim. 3:14 - continue in what you have learned and believed knowing from whom you learned it (by oral tradition).
1 John 2:7 – John refers to the oral word his disciples have heard which is the old commandment that we love one another.