It is not missing anything necessary because as I have indicated John says this Gospel is enough. And yes, I am saying that Tradition is not required. That does not mean it cannot contain truth, but what is necessary is in the Bible. The Bible itself contains truth that I don’t think is necessary for salvation. For example, Numbers tells us how many of each tribe of Israel left Egypt. That is contained in divine revelation, but is it necessary that we know it?
John says HIS gospel is enough. Is this a statement, in and of itself, that anything else is not enough? You’ve said no. So is this a statement, in and of itself, that anything else is not necessary?
Was Mary sinless. Tradition would say she was. People would argue that “full of grace” implies this. However the Bible also says that everyone except Jesus has sinned. She may have been without sin but since it is not clear from the Bible it is also not necessary to believe it.
It is necessary to believe God, period. What I’m trying to discuss with you is where is God’s total and complete revelation contained?
There is also the question of what would actually be Tradition vs traditions of men. We are warned against traditions of men.
Just as you trusted the Church to define scripture for you (as in what books are in it), it would be the same for Tradition vs. tradition, if you were to come to a point where you would believe that Tradition is necessary truth along with scripture, both being under the interpretative (is that a word?

) authority that God placed over it. So just as the Church defined what scripture was truth, it also defines what tradition is truth.
Was Mary ever virgin? The Bible contains statements talking about brothers of Jesus. Tradition says that Mary had no other Tradition, However what is the actual Tradition?Up until Jerome it was generally viewed that these brothers were step-brothers; children of Joseph by an earlier marriage. Then Jerome says that they are really cousins. Why the change? What was the actual tradition?
The first is actual, documented dogma of the Church, declared openly by the Church as a truth revealed through God’s orally communicated word (Tradition).
The second is pointless, it doesn’t matter. Cousins or stepchildren are still not biological children, which in effect leaves Mary still a virgin, neither changes this state.