Nobody in Scripture teaches the idea that Scripture stands alone. .
Actually the only transcendent substantive body of Truth that the Spirit of God affirms is wholly inspired of Him is that which is called Scripture. Certainly SS (sola scriptura, reasonably defined) does does not exclude helps to understand Scripture, and thus the church, teachers, and the magisterial office, etc. But as said, it is
abundantly evidenced that as written, Scripture became the transcendent supreme standard for obedience and testing and establishing truth claims as the wholly Divinely inspired and assured, Word of God.
Which is sufficient in its formal and material aspects combined, and reveals and materially provides writings being recognized as being of God, and thus for a canon.
Scripture says to hold fast to the traditions just as they were given, whether orally or by letter.
Which, with its presuppositions, was much
dealt with at length (and ignored) on the last page, and one of the problems is that this not only presumes that 2Thes. 2:15 is not simply referring to oral preaching of Scriptural truths, obedience to which a SS preacher may also enjoin, even of those who have no Bible, but with the veracity of which dependent upon Scriptural substantiation in word and in power. Which is what the NT established its Truth claims by.
And while Rome does not presumes to be passing on new revelation, or speak under the manner of inspiration that Scripture enjoys, yet she (or RCs) presume that 2 Thes. 2:15 (and 1Co 11:2) refer to such things as the IM and Assumption of Mary, and not to what was or would be written in Scripture, which is abundantly affirmed to be the case with any revelation called "the word of God/the Lord."
Thus the answer to your question "do you agree with the Bible that we should hold fast to the traditions as they were handed on, whether orally or by letter" as being the word of God, is yes, since this very text comes from Scripture, and which is the assured word of God and we can expect would contain these orally preached Truths where those which would be, or already were, contained in Scripture.
But the problem your question is that it uses 2 Thes. 2:15 as carte blanche for Rome to decree what it wants to as being binding doctrine, and so that your question really is, "do you agree that we should hold fast to whatever traditions the RCC says were handed on, whether orally or by letter."
And which does not simply mean a set of doctrines that cannot be shown to be what Paul referred to or the like, but it also means whatever Rome comes up with in the future.
And (this is key for a RC) that the basis for the veracity of such is that of the novel premise of ensured perpetual magisterial infallibility, which is unseen and unnecessary in Scripture.
Consider the case of the Assumption, which was declared a binding doctrine approx. 1700 years after an event allegedly occurred, even though it is
lacking in early testimony and was opposed by Rome's own scholars.
Ratzinger writes (emp. mine),
Before Mary's bodily Assumption into heaven was defined, all theological faculties in the world were consulted for their opinion.
Our teachers' answer was emphatically negative . What here became evident was the one-sidedness, not only of the historical, but of the historicist method in theology. "Tradition" was identified with what could be proved on the basis of texts
. Altaner, the patrologist from Wurzburg¦had proven in a scientifically persuasive manner that the doctrine of Mary's bodily Assumption into heaven was unknown before the 5C; this doctrine, therefore, he argued, could not belong to the "apostolic tradition. And this was his conclusion, which my teachers at Munich shared.
...But if you conceive of "tradition" as the living process whereby the Holy Spirit introduces us to the fullness of truth and teaches us how to understand what previously we could still not grasp (cf. Jn 16:12-13) [meaning grasping extraScriptural fables to make them binding doctrines], then subsequent "remembering" (cf. Jn 16:4, for instance) can come to recognize what it has not caught sight of previously [meaning the needed evidence was absent] and was already handed down in the original Word." [via amorphous oral tradition] - J. Ratzinger, Milestones (Ignatius, n.d.), 58-59.
That is the living word of God. So our job is to find the true Church and hold fast to what she hands on to us, whether in writing or orally.
That is your very problem. The veracity of such traditions rests upon the tradition of of ensured perpetual magisterial infallibility, by which you are assured the Assumption is true, regardless of even the lack of warrant for it. Which is not how the NT church began, but it what cults operate under!
So I have to hold fast to the traditions, whether given orally or by letter, because that's exactly what Scripture and the Church say. Otherwise I would not be following the Word of God.
That is absurd, as "the word of God" is not that which was established on the basis that the writings of Scripture were which the NT church appealed to, but "the word of God" is whatever Rome says it is, since she has presumed to infallibly declare she is and will be perpetually infallible whenever she speaks in accordance with her infallibly defined (scope and subject-based) formula, which renders her declaration that she is infallible, to be infallible, as well as all else she accordingly declares.
The Word of God teaches that Mary is the Immaculate New Eve
Rather, Rome says she is, and thus you must believe it, but the wholly inspired word of God does not teach the IM.
As Scripture says, she is named "Having-Been-Endowed-With-Grace" and "She Who Believed"
Which is not unique of Mary,
nor does Scripture say she is "full of grace" which it says of the Lord Jesus. (Jn. 1:14)