(YOU WROTE:) "But when the Church Fathers put together the Canon of the bible, why didn't they pick some of those writings that are more explicit about the intercession of angels and saints?"
-- Ah, but they did! This is what I didn't understand as a Protestant; the early Church held to the Septuagint, or Gk translation of the Hebrew OT, which included what we call the Deuterocanonical Books, aka the Apocrypha, in which are included said "writings that are more explicit." In fact, this was one of the main differences between the Christians and the Jews of the first several hundred years AD. Origen put it this way:
"When we notice [discrepancies between the Hebrew and Greek OT's], [are we] forthwith to reject as spurious the copies in use in our Churches, and enjoin the brotherhood to put away the sacred books current among them, and to coax the Jews, and persuade them to give us copies which shall be untampered with, and free from forgery[?] Are we to suppose that that Providence which in the sacred Scriptures has ministered to the edification of all the Churches of Christ, had no thought for those bought with a price, for whom Christ died...?"
You see, Neander, the Greek Septuagint (LXX -- so called because 70 (LXX) rabbis supposedly translated it identically) was the OT that the NT writers quoted from, not the Hebrew Masoretic text (Masor.), when referring to prophecies about Jesus (prophecies which are NOT THERE in the Hebrew). Since it was the OT of the Apostles, it became the OT of the first believers by default...and it included the Apocrypha, which was quoted AS SCRIPTURE by many of the Church's first bishops!
The Masor. (w/out Apocrypha) was decided on later, BY THE JEWS, as a reaction to the Church's insistence on Messianic prophecies being fulfilled via the LXX. The Church cared not a whit what unbelievers said in matters of faith and doctrine, and were happy to stay with what they had been given, as Origen said. The reason Protestants traditionally reject the Deuterocanonical books is because Martin Luther, going against 1500 years of uniformity within the Church, supposed that the "Jews should know their own Scriptures" and took out the Apocrypha because it didn't go with his beliefs.
(YOU WROTE:) "At the time of the Early church there were many false teachings and doctrines going round...how can a lay person today distinguish what thought and practise comes from a false teaching and what doesn't? The only safe ground here is the books of the Bible."
-- OK, granted, but which Bible? More to the point, whose interpretation of which Bible?
As Mor Ephrem stated, the Canon of the NT itself was all OVER the place until around 325 when it was uniformly accepted in its present form. That answers "which Bible."
St. Vincent of Lerins answers the "which interpretation" question by asking, "since the canon of scriptures is complete, and is in itself adequate, why is there any need to join to its authority the understanding of the church? Because Holy Scripture, on account of its depth, is not accepted in a universal sense. The same statements are interpreted in one way by one person, in another sense by someone else, with the result that there seem to be as many opinions as there are people...Therefore, on account of the number and variety of errors, there is a need for someone to lay down a rule for the interpretation of the prophets and the apostles in such a way that it is directed by the rule of the catholic church."