Regarding teenagers masturbating, since they supposedly have no need for ejaculating before marriage, why would God give them the ability beforehand? It serves no useful purpose. Murdering someone = killing someone, although for unacceptable reasons. And killing someone is sometimes necessary (e.g., in defence of yourself or others).
I don't know about Protestantism, but Catholics believe the Old Testament points forward to the coming of Christ. Verses take on a whole new meaning when read from that perspective. Some scholars think there may be more than 300 prophecies about Jesus, but it goes beyond that. If you know what to look for, much more of the Old Testament is believed to be about the coming of Christ, even when the verses don't seem to be about that. It's been too long since I read that, so I don't remember any examples.
So, the fact that Catholic Bibles include more books than Protestant ones means some of those prophecies and verses that point forward to Christ are disagreed upon by the two major denominations. They can't both be right, can they? If either one of them is incorrect, then billions of Bibles are in error. Given the many denominations in Christianity, especially in Protestantism, and given that many of those denominations arose as a result of differences in the interpretation of the Bible, that supposedly inerrant book has led to billions of people being led astray. Granted, the Bible could still be inerrant, even though most or all denominations (save for one) are interpreting it incorrectly, but what's the point of declaring the Bible inerrant when billions of Bibles may be wrong, and there is no consensus as to which denomination actually has the correct Bible and no way to find out so as to reach a consensus.
Just to be clear, I'm putting forth Connor's arguments, not my own. I may even have him declare the Bible to be full of errors at some point. He'll definitely espouse beliefs that conflict with the Bible, but he won't push the envelope so far that most people would conclude he's not Christ. He's merely using his arguments as a means to an end: follow him, not some ancient book.