OK, I have to admit that Paul isn't my favorite apostle. He comes across as misogynistic, legalistic, and the first Christian Pharisee...dragging all his previous biases in with him when he converted. If and when I do ever meet him, I'll have a few pointed comments to make. As well, you are right that there is zero evidence that he actually met Jesus (though he probably saw Him, at least, and almost certainly knew about Him during His lifetime). My opinion of his personality aside, however, Paul's position as an apostle is based upon his actually receiving revelation FROM Jesus Christ, as the other apostles did, according to Acts. If he did receive that revelation, then he 'met' Christ, whether or not I want to drop water balloons at him from a great height. The problem is, the bible, when talking about prophets and apostles, goes to some lengths to point out the human flaws in the people God chooses to use, and Paul, irritating as he is, fits right into that particular pattern.
The question you are raising, though, is an important one for me. Are you saying that only those who actually met and followed Jesus during His lifetime are qualified to be apostles/prophets, and to have contributed to scripture?
As well, while I agree with you that the books were compiled into what we know as 'the bible' partly for the reason you state, I don't think that this is why those books and letters were actually written. (large font for JoStories)