Blood atonement and Adam/God theory has been answered many times. All you have to do is look for the responses from the LDS church to find out about them.
They were taught by Brigham Young
The keys were given to the 12 Apostles under Joseph Smith.
Mormons claim their Apostles hold the key of Priesthood Authority which the Catholic Church lost; demonstrated by the fact there are no more Apostles in Orthodox Christianity. The problem with this claim is Mormon history itself.
In 1830, Joseph Smith started the Latter-Day-Saint Movement by making himself First Elder and Oliver Cowdery ‘Second Elder.’ They both claimed to be given the ‘Keys.’ Smith established the First Presidency, Jesse Gause and Sidney Rigdon, to run the Church in 1832. This High Council was the chief judicial and legislative body of the church supervised by the First Presidency. The Presiding High Council was established in 1834 by the First Presidency. In 1835, Smith told Oliver Cowdery, Martin Harris, and David Whitmer, to select the Twelve Apostles to head the missionary work of the Church. The first apostles were: Brigham Young, Heber C. Kimball, Lyman E. Johnson, David W. Patten, Orson Hyde, William E. M’Lellin, Luke S. Johnson, William Smith, John F. Boynton, Parley P. Pratt, Orson Pratt, Thomas B. Marsh.
By the end of 1835, the Church was run by the Elders in the First Presidency who was over the Elders in the Presiding High Council who was over the Quorum of Twelve Apostles. ‘The Keys’ were held by the First Presidency who were not ‘Apostles.’
In 1837, the failure of the Kirtland Safety Society, a bank founded by church leaders, led to widespread dissent.
In 1838, Thomas Marsh, Luke Johnson, Lyman Johnson, William M’Lellin, and John Boynton were excommunicated. And John Patten was killed. They were replaced by John Page, and John Taylor leaving the church with eight apostles.
In 1839 Wilford Woodruff, and George Smith were added to the Quorum of Twelve Apostles to make the total number ten.
In 1840, Willard Richards made the number of apostles eleven.
In 1841, Lyman Wight was added to restored the number of apostles to twelve.
In 1842 Orson Pratt was excommunicated and replaced by Amasa Lyman.
At the time of Joseph Smith’s death the First Presidency included: Joseph Smith, Hyrum Smith, and Sidney Rigdon. The head of the Presiding High Council was William Marks. The head of the Quorum of the Twelve Apostles was Brigham Young. After the Smith’s were killed, only Sidney Rigdon remained in the First Presidency.
As the member of the First Presidency (holder of the keys) Rigdon claimed to be guardian of the church and Apostle John Page and Elder William Marks supported him in that claim.
Brigham Young as the head Apostle claimed Joseph Smith was an Apostle and held the keys. Because Young was the head Apostle he claimed to replace Smith as the holder of the keys. This was the first time any Mormon thought of an Apostle as being a key holder.
The Church membership voted for Young, as leader of the third level church council, to lead the church; and raise the Quorum of Twelve Apostles over the Presiding High Council while taking over the First Presidency.
To summarize: Five years after the start of the Mormon Church, Smith invented the position of Apostle. The Quorum of Twelve Apostles ran the missionary effort of the church, not the whole church. The Apostles did not hold ‘the keys’ during Smith’s lifetime. The association of ‘keys’ with ‘apostles’ was an invention by Brigham Young to get control of the Church.