Great topic, I'm taking a class this term that covers the same general things. A few other questions you could ask are:
What effect, if any, does the translation have on the authenticity of the languages, i.e., when the Gospels were taken from Hebrew/Greek/Aramaic to Latin, and so on to English, was there anything lost in the translation, either linguistically (things that wouldn't translate well into the other language) or culturally, i.e. common trends, etc that had no equivalent in the culture the N.T. was being translated to?
And also, what about the other books that didn't make it into the New Testament - the so called "Gospel Of Thomas" among others. What makes Matthew, Mark, Luke and John more reliable than these, and what are/were the criteria for adding/excluding books to the new Testament?

(p.s. If you want any help from your topic, let me know - that class answers a bunch of your questions.)