The old Catholic church traditions are worth more than all you have said. Here is a principle of logic that most men have no more sense than to adopt. I will illustrate it by an old apple tree. Here jumps off a branch and says, I am the true tree, and you are corrupt. If the whole tree is corrupt, are not its branches corrupt? If the Catholic religion is a false religion, how can any true religion come out of it? If the Catholic church is bad, how can any good thing come out of it? [...] Any man who will betray the Catholics will betray you.

Joseph Smith, History of the Church, vol 6, p. 479
http://byustudies.byu.edu/hc/6/24.html

“[I]ndividual orientation to the Church of the Lamb or to the great and abominable church is not by membership but by loyalty. Just as there Latter-day Saints who belong to the great and abominable church because of their loyalty to Satan and his life-style, so there are members of other churches who belong to the Lamb because of their loyalty to him and his life-style. Membership is based more on who has your heart than on who has your records.”

Stephen E. Robinson, 
“Warring against the Saints of God,” Ensign, Jan 1988, 34.
http://www.lds.org/ensign/1988/01/warring-against-the-saints-of-god?lang=eng

“Informed Latter-day Saints do not argue that historic Christianity lost all truth or became completely corrupt. The orthodox churches may have lost the ‘fullness’ of the gospel, but they did not lose all of it nor even most of it. Many Evangelicals caricature or overstate the actual LDS view, which is that the orthodox churches are incomplete rather than corrupt. It is their postbiblical creeds that are identified in Joseph Smith’s first vision as an ‘abomination,’ but certainly not their individual members or their members’ biblical beliefs.”

Stephen E. Robinson
Craig L. Blomberg and Stephen E. Robinson, How Wide the Divide? A Mormon and an Evangelical in Conversation (Downers Grove, IL: InterVarsity Press, 1997)
http://www.mormonnewsroom.org/article/authority-in-the-church

“The line of priesthood authority was broken. But mankind was not left in total darkness or completely without revelation or inspiration. The idea that with the Crucifixion of Christ the heavens were closed and that they opened in the First Vision is not true. The Light of Christ would be everywhere present to attend the children of God; the Holy Ghost would visit seeking souls. The prayers of the righteous would not go unanswered.”

Boyd K. Packer, “The Light of Christ,” Ensign, Apr. 2005, 11
https://www.lds.org/liahona/2005/04/the-light-of-christ?lang=eng&query=Inspiration