I would ask the following since you seem both knowledgeable and reasonable:
1. If kindsmen, cousins, etc. would be the correct translation, why is the word BROTHER used since it has a very specific meaning today?
Why not say: Blood relative for instance, which could mean a cousin.
"kinsman/kinswoman, or relative" is one of the
definitions, it's not a translation, of the Koine Greek word
"ἀδελφοί" (adelphoi), or
"brothers", and it can refer to various types of family members. That's why one shouldn't just assume that the word
"ἀδελφοί" refers to siblings, or any other type of family member in any given verse where that definition applies. Unfortunately, there are people who make the mistake of assuming that a
modern-day familial definition of the modern-day word
"brother" applies to the
archaic Koine Greek word for
"brother".
Refer back to post #4 where in it I present scriptural verses, and the testimonies of early Christian Church fathers, that collectively show Jesus's brothers (kinsmen/relatives) Joseph, Simon, James, and (Jude/Thaddeus) were the sons of His uncle, Alphaeus, and his wife, Mary.
2. WHY is it so imperative that Mary not have had other children in the Catholic faith?
The perpetual virginity of Mary is a Truth passed down orally and traditionally for over two thousand years. In modern times, Jesus Himself, on February 13th, 1949, confirmed it once again to His spokesperson Maria Valtorta saying, "Can it be admitted that She who was preordained to be the divine form for the Second Person to become flesh could accept the seed of a man in Her womb, which had been divinised by God taking form in it, and have a human son conceived in original sin through inheritance from Adam? How could the Immaculate have generated an impure son from Her womb? How could the eternal Virgin accept human intercourse after having known the embrace of God? She Who from eternity we thought of as "our dwelling" could only be of God. Only God Incarnate could be formed and born from the Most Holy Mary."
Jesus has spoken in depth to Maria Valtorta about His Mother and many other topics. It's all quite enlightening and beautiful.
3. Some Catholic theologians (I named one before) can accept that these brothers were the children of Joseph by a previous marriage.
I can't remember if you also deny that....if so, why?
It's my understanding that Jesus's brothers were not sons of Joseph from a previous marriage, for reasons some of which have been presented in post #4.
For instance...a good reason to believe Mary had no other children is the fact that Jesus gave John the task of caring for Mary (from the Cross) and V V. This would seem to indicate that, indeed, Jesus was the only child of Mary....in ANY regard.
While you might believe Jesus placing His Mother in the care of John of Zebedee indicates that He
didn't have siblings, there are others who believe it indicates that He
did have siblings, but either didn't trust them, or didn't like that they were unbelievers, which is why He didn't choose any of them to take care of Mary. Prior to what I learned, I never believed that the latter was the case, and what I came to learn confirmed that it wasn't. On February 24th, 1944, Jesus dictated to His spokesperson Maria Valtorta why He chose John of Zebedee to care for His Mother as a son:
"Look at the lively delicate sensitiveness of John's behaviour from the Thursday night to the Friday night. And further. But let us consider it during those hours.
A moment of dismay. An hour of dullness. But after he overcomes sleepiness through the excitement of the arrest, and the excitement through love, he comes, dragging Peter with him, so that the Master may have some comfort seeing the Head of the apostles and the Favourite apostle.
He then thinks of the Mother, to Whom some cruel person may shout that Her Son has already been captured. And he goes to Her. He does not know that Mary is already living the tortures of Her Son and that while the apostles were sleeping, She was awake and was praying, agonising with Her Son. He does not know. And He goes to Her and prepares Her for the news.
Then he goes to and fro from Caiaphas' house to the Praetorium, from Caiaphas' house to Herod's palace, and then again from Caiaphas' house to the Praetorium. And to do so that morning, elbowing his way through a crowd intoxicated with hatred, wearing garments that point him out as a Galilean, is not pleasant. But love supports him, and he does not think of himself, but of Jesus' and His Mother's sorrows. He could be stoned as a follower of the Nazarene. It does not matter. He defies everything. The others have run away, they are hiding, they are led by prudence and fear. He is led by love, and he remains and shows himself. He is pure. Love thrives in purity.
And if his pity and common sense of a man of the people persuade him to keep Mary away from the crowds and from the Praetorium - he does not know that Mary shares all the tortures of Her Son, suffering them spiritually - when he decides that the time has come when Jesus needs His Mother, and that it is not right to keep the Mother any longer away from Her Son, he takes Her to Him, he supports Her, he defends Her.
What is that handful of loyal people: a man all alone, unarmed, young, with no authority, leading a few women, with respect to a furious crowd? Nothing. A little pile of leaves that the wind can scatter. A small boat on a stormy ocean that can sink it. It does not matter. Love is his strength and his sail. He is armed with it, and with it he protects the Woman and the women until the end.
John possessed the love of compassion as no other person, except My Mother, possessed it. He is the Head of those who love with such love. He is your master with regard to that. Follow him in the example he gives you of purity and love, and you will be great.
Go in peace, now. I bless you." (
The Gospel as Revealed to Me, or
The Poem of the Man-God: Vol. V)
(
Note: see the first four links in my signature for proof that Maria Valtorta was a spokesperson for Jesus.)