Actually, a "testament" is nothing more than a record in which someone testifies or witnesses to the truthfulness of something he knows to be true. We have four of them in the Bible alone: Matthew, Mark, Luke and John. Each of them is an account of the life of Christ. Each of them is from a different perspective and not all of them touch on the same events as the others. I don't see many Christians tearing Luke's account of the Annunciation to Mary or of Mary's visit to Elizabeth, just because Matthew, Mark and James don't mention them. Given the fact that the vast majority of the events in the Book of Mormon supposedly happened on the other side of the world and were unknown prior to 1829, it's hard to conclude, as you have, that they cannot be considered scriptural.
First off, you're looking at the Book of Mormon as if it were a nineteenth-century revelation, which it isn't. Suppose another of Paul's epistles were to be discovered in the Holy Land and that Christian scholars (Catholic, Protestant, LDS, etc.) all agreed that it was not a fraud, but Paul's actual letter to the Laodiceans (as mentioned in Colossians 4:16). Would you consider it to be "new doctrine" just because it was discovered in the twenty-first century?
And how long did it take Apostolic tradition to determine that God was through talking?
That's pretty blunt, all right. Would you give an example of something in the Book of Mormon that contradicts God's word? Or are you saying that it contradicts God's word merely by its existance?
Again, when did God say that He would never again have anything to say to the Church as a whole? And why did Jesus prophesy that the prophets He would send would be rejected, if He never intended to send them in the first place?
Yeah, we're a pretty decent lot, aside from the fact that we try to deceive people into thinking we're Christians. Anyway, I'm glad you enjoyed your experience at the LDS worship service. I'm actually going to an Advent Mass the day after tomorrow with my son's Catholic girlfriend (whom I want desperately for him to marry). She's coming to the Tabernacle Choir's Christmas Concert with us in the morning, and then we're going to mass with her in the evening. I think we're all looking forward to the exchange.