Uh, wow. When the cat's away, the mice will sit around and ask lots of questions.
To C3PS, I had hoped to type up the argument for the Book of Abraham myself, but as it is already probably the longest point to make and so many things have been brought up, I will briefly summarize my stance and refer you to this website, which also has responses to numerous other criticisms. The link I gave you specifically refers to the Book of Abraham, but look around and you might find some other interesting info. Anyway, to sum up the possibilities, it must be first acknowledged that only a fraction of the total number of papyrus scrolls Joseph Smith had have been found. Thus, the following theories, taken from the linked website, include that fact:
"1) The text was revealed much in the same manner as that of the Book of Mormon, without the need for the actual papyri, 2) The text was present on portions of the papyri that are missing, and 3) The Book of Abraham manuscript was attached to the Book of Breathings manuscript and was lost. 4) Perhaps there was a way of understanding the Egyptian ideograms anciently that is unknown to Egyptology in our day, yet to be discovered, deciphered or acknowledged, that could yield an interpretation of a text that is different than the standard Egyptological reading."
My interpretation is essentially the first theory. According to the Book of Abraham, Abe taught the Egyptians astronomy and many sciences, as well as the nature of God (some of this is actually stated by Joseph Smith, since the Book itself was never completely published). If he taught them and there was any acceptance of it, many of their sciences would be influenced by his teachings. The actual scrolls date from much later than Abraham's time. Thus, in my opinion, they are actually what remained of his teaching couched in Egyptian mythology. Joseph Smith's translation was likely a restoration of what Abraham's original message had been. This website here shows a number of surprising parallels between Joseph Smith's translation and what Egyptologists have deciphered. Hope this is at least a good starting point for you.
In response to Frink's inquiry, I'm sure I will take flak for this, but sometimes a person of faith acts on faith, even if they are not sure why. Sometimes God simply wishes to test our obedience. Looking at the kosher laws of the Old Testament, God did not mention how much cholesterol or the various parasites you might find in pork. They simply obeyed because God wanted them to. "Oh no! Blind faith!"
More to follow soon...