Your scenario of a probable way in which the l44,000 are annointed
seems good to me!  You say they will be Jewish rabbis or other
spiritual heads of the Jewish people, who suddenly, like Saul of
Tarsus, their model, will have visions of the Lord and accept him.
This sounds right.

You say a person is a Jew only if born a Jew.  On this one point I
would like to offer an amendment.

In today's world, many Jews (identified as those who are Torah
accepting but not New Testament accepting) are not "born Jews".

Orthodox Jewish law says that a person is Jewish only if his/her mother
is a Jew.  (Reform Judaism accepts as born Jews those whose father was
Jewish, as well).  Today, many Jews are converts or or born of a
gentile mother and a Jewish father.  This is a very large portion of
the Jewish population, even if one considers only those who are Torah
adherent.  And it has been the way throughout history, starting in
Egypt and the Exodus.   Abraham was the first convert--maybe Sarah was
the second, or third after Lot?

Having come from a Jew-rich culture (40% of my high school was Jewish)
and having married a man who had a Jewish father and a blonde Lutheran
mother, and being step-mother to a woman who converted to Judaism at
the age of 20 and had four Jewish children, this enigma has been part
of my life.

My husband (the one with the Jewish father and gentile mother, hence
not a Jew in orthodox terms) had a grandfather who was a devout Jew and
who founded a synagogue in Appleton, Wisconsin.  Grandfather Strauss'
wife was a Levi.  Levi-Strauss, like the jeans--I used to have a
t-shirt with Levi-Strauss on it, but it was finally worn out as an
heirloom donated to my son.  My husband was never raised Jewish, and
did not consider himself Jewish, and attended a Christian church as a
child in Oregon.  And yet, his whole family is aware of and responds in
various ways to being partly Jewish.  Both of his daughters married
Jews, one as a convert, the other as a Christian marrying a Christian
Jew (with dredlocks no less).

I myself probably have Jewish ancestors, although I know of none
proven.  This is because I have a genetic signal which is predominant
among Jews.  I have that "mark".  I only recently discovered this
trait.  I believe that, entirely apart from the whole concept of
British Israel, there are many of us who have Jewish descent which we
do not know about.  But this descent is "mixed" and does not manifest,
to our knowledge, as being "born Jewish".

So, the rabbis who may indeed be the l44,000 may not all be born Jews.
Some may be converts (a minority perhaps).  Some may be the sons of
Jewish fathers and gentile mothers who converted, and even gentile
mothers who did not convert, so that the son would need to become
adherent to Torah.

This will be a spiritual Jewishness in many cases, I think.  The
l44,000 are undoubtedly Jews.  But some may not have been born Jews in
the orthodox sense.