PW,
I think that is an excellent point.
sb / iron,
First of all I greet both of you in brotherly love, and I don't say this to divide us, but to let iron sharpen iron.
I believe that we are to be prepared to answer in a scholarly fashion to those unbelievers or believers who ask us about any aspect of our faith or the Scriptures. First off, I am not one of those who think that 4 men wrote the OT or whatever, I believe that the Bible is the inspired, innerant, incorruptable Word of God. But that was not the question that the brother originally posted. If he had asked if the Holy Ghost had written the entire Bible, of course I would have answered 'yes'.
This said, the reason that I bring up that Moses did not originally pen the book of Genesis, is that he was not alive, obviously. This is not denial as to the inspiration of any of the Torah. I believe it is all inspired of God. The reason that "these are the generations of" is important, is that you will find that phrase 10 times in the book of Genesis, each time with an obvious change in focus and style. This was the beginning of a section from a different author, ie: Adam, Noah, Abraham, Joseph. Why would it be heresy to think that there was a collection of authors for Genesis, when we have a collection of authors for the Canon? The reason that I think that this view I hold is important is that it also shows that each author was eyewitness to what happened.
The more common view is that the book of Genesis was oral tradition handed to Moses from stories told between people. I doesn't bother me that people believe this, but it was never God's way to do this from Moses and onward, so why would it be outlandish to think that "holy men of God spake as they were moved by the Holy Ghost" before Moses was alive.
All this said, and back to my original point, I don't spend alot of time discussing this issue, in fact my focus in much more in Christ being formed in us, prayer, revival, and evangelism, but like I said, I was just answering this brother's question as he asked it.
Also, sb, as far as studying the finer points of the Bible, this is not studying the doctrine of man, but God. For example, how God created man, God first created his body from the dust, and breathed into his nostrils, making man "a living soul". What I see in studying this is a foreshadowing of Christ. God brought Adam from seeming nothingness, just as He did with Christ from the tomb, and somewhat similarly to the birth of Christ. Dear brother, studying this is studying the Word of God. As far as authorship of books, if this is not important then why did God have some men to write their name as author of the book, ie: Luke, Paul, etc? If you don't want to study this, I won't fight you, but I don't think I am less spiritual, or anyone else for reading into the Word of God to study authorship.
God bless.