Predicting Christ's New World visit

Around 600 BC father Lehi saw a vision of Christ and his apostles. He was even told that Christ would come visit the Lehites in the New World 600 years from their departure for the new promised land.

And yet despite that very explicit prophecy for centuries the following prophets are clueless. Look at how out of touch Alma is.

 

Unless everyone else was as ignorant as Alma, why would anyone be impressed by Samuel the Lamanite's prophecy? 

Why would this be? The answer could be as simple as this: Joseph Smith didn't know how he was going to bring about the advent of Jesus in the Americas during the earlier stages of writing The Book of Mormon, but by the time he finished up Moroni and went back to replace the missing 116 pages of manuscript with what became 1 Nephi through Words of Mormon he had the whole thing figured out and could include all the appropriate prophetic details.

Sound doubtful? Good. Doubt your heart out!

Christmas confusion: the star

Mormons believe that there really, truly was a star that appeared at Jesus' birth. They believe this partly because the Gospel of Matthew mentions some astrologers reading his sign in the sky but also because The Book of Mormon treats the star as a real thing.

It all starts out with the sun going down and "great lights in heaven" (Helaman 14:3) keeping things as bright as day. Then we get the Star of Bethlehem showing up sometime later.

The story makes wonderful sense until you stop to think about it. Why does the Bible not mention a night as bright as day? Were the "great lights" Samuel the Lamanite spoke of, like, angels acting as nightlights or something? Third Nephi doesn't say. Why would Herod's astrologers be the only assholes able to see and understand the significance of a mega-bright star showing up in the sky? Why should we believe that star-reading, horoscoping assholes had any valuable insight about the future at all, ever? Why would said astronomers need a star to travel ten miles down the road, anyway? Why doesn't Samuel the Lamanite give any instructions on how to read the "many signs and wonders in heaven" (Helaman 14:6)? Is a new savior being born every time a supernova pops or a meteor shower hits? Does God really relay messages of truth through the stars? If so, it would seem that modern-day astronomers and modern-day prophets are both having a hell of a time making heads or tails of what God's trying to tell us via astroscript.

What if it's all just a fun story? What if The Book of Mormon is just another fun story based off of a fun story or two?