A few comments:
1) Statements and writings from a Mormon Apostle, from a past President of the Mormon Church, and from Brigham Young don't exactly count as "off the cuff" quotes, in my book. They sound like they're reiterating serious, even if "non-canonical" statements of belief.
2) I'm sure there were a lot of Protestants and Catholics who owned slaves too. But most of them stopped considering blacks as spiritual second class citizens before the 1970s.
3) While I (obviously) disagree with Mormonism, I think Huckabee is way off the mark and is really shooting himself in the foot with his attacks on Romney. Theology isn't really pertinent to the Presidency.
However important you make comments sound, they are not important unless adopted by the church in Gen. Conf. None of your quotes rise above opinion, no one knew why the Lord kept the Priesthood from Blacks until the time was right. I quit trying to figure out why the Lord does what he does. Alot of people speculated as to the reasons, Blacks were never second class citizens in the church they functioned like everybody else they just did hold PH until 1978. We did not segregate like the protestants did. Looking back many years the comments look and sound ridiculous, but alot of things look silly with 20/20 hindsight.