My only exception to what you say is that I find no place in the Bible where we are to judge each other. As to the BOM, I don't know. Judgement of one another is usurping the power of God. I mean that as harshly as I can.
Actually, the Bible is filled with examples of the Lord commanding His people to judge righteously.
After the the Lord promised Abraham that his seed would become a mighty nation, the Lord said of his children,
"For I know him, that he will command his children and his household after him, and they shall keep the way of the Lord, to do justice and judgment; that the Lord may bring upon Abraham that which he hath spoken of him." (Genesis 18:19)
This idea was reiterated to the children of Israel (Abraham's descendants) through Moses after the Law was given,
"Ye shall do my judgments, and keep mine ordinances, to walk therein: I am the Lord your God." (Leviticus 18:4)
As long as we live after the Lord's way, keeping His judgments and ordinances, we will judge righteously and justly.
The Lord went into further explanation to the children of Israel when He said,
"Ye shall do no unrighteousness in judgment: thou shalt not respect the person of the poor, nor honour the person of the mighty: but in righteousness shalt thou judge thy neighbour." (Leviticus 19:15)
They were expressly commanded to judge their neighbors as long as they did so in righteousness.
The Lord Jesus Christ spoke on this subject as well, claiming that with whatever judgment we use to judge others we shall also be judged.
"For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again." (Matthew 7:2)
The Lord Jesus Christ actually condemned the Pharisees because they reserved judgment, among other things,
"Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone." (Matthew 23:23)
The Lord basically boiled the general rule of judgment to this,
"Judge not according to the appearance, but judge righteous judgment." (John 7:24)
As to the Book of Mormon, during His bodily visitation to the people of Nephi, the Lord taught,
"And now behold, this is the commandment which I give unto you, that ye shall not suffer any one knowingly to partake of my flesh and blood unworthily, when ye shall minister it;
For whoso eateth and drinketh my flesh and blood unworthily eateth and drinketh damnation to his soul; therefore if ye know that a man is unworthy to eat and drink of my flesh and blood ye shall forbid him.
Nevertheless, ye shall not cast him out from among you, but ye shall minister unto him and shall pray for him unto the Father, in my name; and if it so be that he repenteth and is baptized in my name, then shall ye receive him, and shall minister unto him of my flesh and blood.
But if he repent not he shall not be numbered among my people, that he may not destroy my people, for behold I know my sheep, and they are numbered." (3 Nephi 28-31)
We believe that those called to serve and administer in the Lord's Church are also called to be judges, to judge members of the congregation, to ascertain if they are worthy to partake of the Sacrament.
These judges are held accountable for any among them who eat and drink unworthily.
I had a time in my life when my Bishop forbade me to partake of the Sacrament. I underwent a period of repentance.
I refrained to partake of the Sacrament until he felt that I was again worthy to do so.
Anyone who is actively engaged in a homosexual lifestyle is committing grievous sin and are not worthy to partake of the emblems of Christ's sacrifice.
If they refuse to repent of their sin their names may eventually be removed from the membership of the Church.