They're being exhorted to stand firm, and hold to traditional teaching in scripture, here. It's not in any way a rationale for the Roman Catholic Church acquiring later traditions that are at variance with scripture.
Are you talking about two meanings of traditions? I believe that is answered above.
What is Tradition?
In this discussion it is important to keep in mind what the Catholic Church means by tradition. The term does not refer to legends or mythological accounts, nor does it encompass transitory customs or practices which may change, as circumstances warrant, such as styles of priestly dress, particular forms of devotion to saints, or even liturgical rubrics. Sacred or apostolic tradition consists of the teachings that the apostles passed on orally through their preaching. These teachings largely (perhaps entirely) overlap with those contained in Scripture, but the mode of their transmission is different.
They have been handed down and entrusted to the Churchs. It is necessary that Christians believe in and follow this tradition as well as the Bible (Luke 10:16). The truth of the faith has been given primarily to the leaders of the Church (Eph. 3:5), who, with Christ, form the foundation of the Church (Eph. 2:20). The Church has been guided by the Holy Spirit, who protects this teaching from corruption (John 14:25-26, 16:13).
Not so. It was the early Church Fathers who consulted tradition and decided which books would constitute the Bible. The Bible did not fall out of the skies. It was authoritatively decided by the Church founded by Christ and inspired by Divine Revelation.