I hadn't read all the way through that thread, I only looked at the OP. Now that I have looked at it, I have noticed that my observation had already been made by others in that thread, and that you had acknowledged it. As for Joseph Smith's lineal descent is concerned, it is pretty standard LDS doctrine that he had descended from Joseph the son of Jacob that was sold into Egypt. That is taught in the Book of Mormon:Benjamin Seeker wrote:Hi, this discussion has already gone on in the other thread. Before I respond, I'd like to point out that you've come out swinging at me as "so unintelligent that [i] can't see something so plain and obvious..." I think we're all allowed to make mistakes, so let's point things out intelligently and see if others respond in kind rather than hurl insults from the get go. Also, though I certainly am a critical thinker, I'm not a full-on critic. I am an active member of the church, just with some very different view points than your typical TBM.
Anyways, here is the relevant discussion:
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2 Nephi 3:
6 For Joseph truly testified, saying: A seer shall the Lord my God raise up, who shall be a choice seer unto the fruit of my loins.
7 Yea, Joseph truly said: Thus saith the Lord unto me: A choice seer will I raise up out of the fruit of thy loins; and he shall be esteemed highly among the fruit of thy loins. And unto him will I give commandment that he shall do a work for the fruit of thy loins, his brethren, which shall be of great worth unto them, even to the bringing of them to the knowledge of the covenants which I have made with thy fathers.
8 And I will give unto him a commandment that he shall do none other work, save the work which I shall command him. And I will make him great in mine eyes; for he shall do my work.
9 And he shall be great like unto Moses, whom I have said I would raise up unto you, to deliver my people, O house of Israel.
10 And Moses will I raise up, to deliver thy people out of the land of Egypt.
11 But a seer will I raise up out of the fruit of thy loins; and unto him will I give power to bring forth my word unto the seed of thy loins—and not to the bringing forth my word only, saith the Lord, but to the convincing them of my word, which shall have already gone forth among them.
12 Wherefore, the fruit of thy loins shall write; and the fruit of the loins of Judah shall write; and that which shall be written by the fruit of thy loins, and also that which shall be written by the fruit of the loins of Judah, shall grow together, unto the confounding of false doctrines and laying down of contentions, and establishing peace among the fruit of thy loins, and bringing them to the knowledge of their fathers in the latter days, and also to the knowledge of my covenants, saith the Lord.
13 And out of weakness he shall be made strong, in that day when my work shall commence among all my people, unto the restoring thee, O house of Israel, saith the Lord.
14 And thus prophesied Joseph, saying: Behold, that seer will the Lord bless; and they that seek to destroy him shall be confounded; for this promise, which I have obtained of the Lord, of the fruit of my loins, shall be fulfilled. Behold, I am sure of the fulfilling of this promise;
15 And his name shall be called after me; and it shall be after the name of his father. And he shall be like unto me; for the thing, which the Lord shall bring forth by his hand, by the power of the Lord shall bring my people unto salvation.
16 Yea, thus prophesied Joseph: I am sure of this thing, even as I am sure of the promise of Moses; for the Lord hath said unto me, I will preserve thy seed forever.
17 And the Lord hath said: I will raise up a Moses; and I will give power unto him in a rod; and I will give judgment unto him in writing. Yet I will not loose his tongue, that he shall speak much, for I will not make him mighty in speaking. But I will write unto him my law, by the finger of mine own hand; and I will make a spokesman for him.
18 And the Lord said unto me also: I will raise up unto the fruit of thy loins; and I will make for him a spokesman. And I, behold, I will give unto him that he shall write the writing of the fruit of thy loins, unto the fruit of thy loins; and the spokesman of thy loins shall declare it.
19 And the words which he shall write shall be the words which are expedient in my wisdom should go forth unto the fruit of thy loins. And it shall be as if the fruit of thy loins had cried unto them from the dust; for I know their faith.
20 And they shall cry from the dust; yea, even repentance unto their brethren, even after many generations have gone by them. And it shall come to pass that their cry shall go, even according to the simpleness of their words.
21 Because of their faith their words shall proceed forth out of my mouth unto their brethren who are the fruit of thy loins; and the weakness of their words will I make strong in their faith, unto the remembering of my covenant which I made unto thy fathers.
22 And now, behold, my son Joseph, after this manner did my father of old prophesy.
It is pretty standard LDS doctrine that these verses have reference to Joseph Smith. The "seer" mentioned in those verses is believed to be Joseph Smith. He is believed to be a descendant of Joseph the son of Jacob through Ephraim, not of David. As for the rest of your comments, the answer is that if you are looking for "polite conversation," you have come to the wrong place to find it! This place is not for that kind of talk.

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P.S.
As far as the priesthood lineage is concerned, more information is given in Section 84:
D&C 84:
6 And the sons of Moses, according to the Holy Priesthood which he received under the hand of his father-in-law, Jethro;
7 And Jethro received it under the hand of Caleb;
8 And Caleb received it under the hand of Elihu;
9 And Elihu under the hand of Jeremy;
10 And Jeremy under the hand of Gad;
11 And Gad under the hand of Esaias;
12 And Esaias received it under the hand of God.
13 Esaias also lived in the days of Abraham, and was blessed of him—
14 Which Abraham received the priesthood from Melchizedek, who received it through the lineage of his fathers, even till Noah;
15 And from Noah till Enoch, through the lineage of their fathers;
16 And from Enoch to Abel, who was slain by the conspiracy of his brother, who received the priesthood by the commandments of God, by the hand of his father Adam, who was the first man—
17 Which priesthood continueth in the church of God in all generations, and is without beginning of days or end of years.
According to the Book of Abraham, a priesthood lineage need not be literal. Those who accept the gospel and received the priesthood then literally become the seed of Abraham. So a literal descent is not a necessary precondition:
Abraham 2:
9 And I will make of thee a great nation, and I will bless thee above measure, and make thy name great among all nations, and thou shalt be a blessing unto thy seed after thee, that in their hands they shall bear this ministry and Priesthood unto all nations;
10 And I will bless them through thy name; for as many as receive this Gospel shall be called after thy name, and shall be accounted thy seed, and shall rise up and bless thee, as their father;
11 And I will bless them that bless thee, and curse them that curse thee; and in thee (that is, in thy Priesthood) and in thy seed (that is, thy Priesthood), for I give unto thee a promise that this right shall continue in thee, and in thy seed after thee (that is to say, the literal seed, or the seed of the body) shall all the families of the earth be blessed, even with the blessings of the Gospel, which are the blessings of salvation, even of life eternal.
D&C 84:
33 For whoso is faithful unto the obtaining these two priesthoods of which I have spoken, and the magnifying their calling, are sanctified by the Spirit unto the renewing of their bodies.
34 They become the sons of Moses and of Aaron and the seed of Abraham, and the church and kingdom, and the elect of God.