Good afternoon rinnie! How has your day been?
Even though your post isn’t addressed to me specifically, I am going to take the liberty of responding. I hope that you do not mind.
Mormons believe that Joseph Smith received his priesthood authority from Peter, James and John, who conferred it upon Joseph by the laying on of hands as resurrected beings. So, perhaps not in the same way as Catholics believe in Apostolic succession, we do believe in Apostolic succession.
We believe in both a written cannon of scripture and in the words of those we believe to be prophets and apostles. In that sense, we do believe both in the written and oral scriptures.
Mormons do not believe in the absolution of sin in the way Catholics do. Although we do believe that a prophet, a stake president, or a bishop can know through revelation if a person has been forgiven by God for their sins. However, we believe that forgiveness can only be given by God, and a priesthood leader can only know God’s will rather than decree forgiveness. In a similar vein, we also believe that through the proper priesthood authority and keys a person can have their “calling and election” made sure. This means that they are guaranteed eternal life.
Mormons do believe we have all necessary sacraments or ordinances required for salvation.
Thanks for your questions.
Kind Regards,
Finrock