Sola Scriptura does not say to throw out anything not written. It says that God's written word is the only authority. Extra-scriptural things can be fine if they do not "offend" scripture. I believe that the opening to Luke is in support of this by taking the step of showing that something must be written in order to be sure. That's authority over all that which is not written. (Of course what is written must be God's word, and in this case, it was.)
As I have already acknowledged, I do not claim that the Luke passage is THE slam dunk for Sola Scriptura, but is useful in general support of it. We have also seen other scripture.
And you are right that Sola Scriptura does place God's written word as the source and arbitrator of all other information. Therefore, everything else must be interpreted through the Bible, rather than the Bible being interpreted through everything else.
I fail to see your distinction between "throwing out unwritten material" and "God's written word is the only authority". And obviously, WHO is to judge whether Scripture has been "offended"? YOU? Clearly, we both have different ideas of whether this has happened. Your view appears to be VERY literal and strict, complying with you preconceived views of man and his relationship (or more accurately, his lack of relationship, with God), while the Church's and St. Paul appears to be more open and more willing to encompass things that were said AND written.
I believe that the opening to Luke is in support of this by taking the step of showing that something must be written in order to be sure.
The reason why Luke writes is not because "people cannot know things that are orally given" but for the sake of organization and more clear reference. I don't find Luke at any time mentioning that oral traditions are to be abrogated. IF this was in his mind, he certainly would have wrote down something to the effect of "ignore any other rumours or teachings not given in written form from now on. They are utterly unreliable and could "offend" the Scriptures that I now write." Nowhere do we get the sense that Luke is writing an account because some people are baptizing babies when they shouldn't be...
As I have already acknowledged, I do not claim that the Luke passage is THE slam dunk for Sola Scriptura, but is useful in general support of it. We have also seen other scripture.
I don't see it supporting SOLA Scripture at all. I see it supporting the utility of written material - but NEVER denying that oral material had its utility AND AUTHORITY as well. It is the APOSTLES who were given the power to bind and loosen, NOT the Bible!
Because you can see out of one eye, should you then get rid of the other? Hardly. The Scriptures AND Apostolic Tradition were given to the Church as a deposit of faith, the Word of God for the Church. By ridding Christianity of part of this sense of God's Word, revelation is no longer clear. This much should be obvious to any person who considers the numerous denominations of Protestantism, even during the time of Luther.
Other Scripture verses have been refuted. It is just not there. Sola Scriptura is a tradition of men. The "Sola" part was never meant as the way that Christians would come to know God. Are you forgeting that people hardly even read the Bible until the 1500's, and these people were quite knowledgeable of the faith as a result of the teachers and practice of the faith.
And you are right that Sola Scriptura does place God's written word as the source and arbitrator of all other information. Therefore, everything else must be interpreted through the Bible, rather than the Bible being interpreted through everything else.
Fantasy that is not done in practice. The very fact that we disagree on Scriptures should point out that Scriptures do not interpret themselves!
Regards