What Authority Permitted Canon Formation?

This is the final answer to my five questions, as I answered it a while ago in my discernment. I will soon try to give Reformed answers to these questions as best as I am able.

5) What authority permitted a definition of Canon, and why are the books therein contained beyond question? Here is an exhausting topic.

The Catholics and Orthodox simply answer that the Church has the authority to define canon. It is interesting to note that the various Orthodox churches have varied canons.

The Protestant churches have used several explanations. I know of four methods (i.e., canon rationale) for arriving at the Protestant list of 66 books.

1) The Westminster Confession of Faith states that "our full persuasion and assurance of the infallible truth and divine authority [of Scripture], is from the inward work of the Holy Spirit bearing witness by and with the Word in our hearts." This is the reformation's canon rationale; we know Scripture when we see it. I sheepishly admit that when I read Revelation and Ecclesiastes, I tend to doubt this inner-testimony doctrine.
2) Prof. R. Laird Harris of Covenant Theological Seminary, in his book Inspiration and Canonicity of the Bible, downplayed the reformation claim as described in The Westminster Confession of Faith, and instead promotes a theory of historical-critical analysis to determine which texts belong in the Bible. Suffice it to say that Canon has been so hotly contested throughout church history that it is not self-evident or even self-identifying. It is not clear what the Jews had for a Canon at the time of Christ’s birth (if such a notion even clearly existed), nor is it clear that Josephus and early Hebrew scholars of the church were not heavily influenced by anti-Christian sentiment within Judaism, particularly against the Christian use of the Septuagint to prove that Christ is the Messiah.
3) Prof. Harris also promotes a view, and I don't know if it is better to refer to this as a complementary or a fall-back argument, that canonicity is determined by Apostolicity. Mark and Luke wrote for Peter and Paul, the argument goes, so are also Apostolic, and thus canonical. James could have been written by the Apostle himself, or by the "brother" of Jesus who is given a special status as an Apostle, the argument goes, such that either way this epistle also should be canonical.
4) Keith A. Mathison, in The Shape of Sola Scriptura, argues that the church was authoritatively reliable in choosing a canon, but only until the fourth century, at which point corruption made it unreliable.

We must concede either that some visible Church authority is responsible for defining a Canon for Christians, or that each individual has to read and reflect upon candidate Holy Books and the history of their acceptance to determine which he might choose as his own rules for normative and moral faith. Authority rests either with the church or the individual. A properly constituted and commissioned Authority is required to define canon, or else we are left with the depressing tailspin noted by R.C. Sproul, that the Bible is a "fallible collection of infallible books." Try explaining that to our relativistic world.

Since the Apostles themselves were not around to define the list of books to be included in Sacred Scriptures, their successors must have. I am loathe to admit this.

However, remember my earlier comment on the Sherlock Holmes inverse analysis. Even if all arguments cut in Catholicism's or Orthodoxy's favor but one, and that one is clearly wrong, those Churches must be wrong. It must mean I've been mistaken about everything else.