Yes they did. The Septuagint contained the "Apocrypha" as well and the Septuagint was used as scripture by the Alexandrian Jews as well as by the authors of the New Testament. No one ever dipsuted a single book of the Septuagint.
You speak as if there was one Septuagint. Though some Hellenized Jews may have read one or more versions of the Septuagint they were hardly the "Jews".
The latter copies available to Origen were written in 2nd century AD (mostly by converts or practicing Jews in an attempt to bring it in compliance with the Pharisaical scriptures), long after the Gospels have been written, and certainly way after Paul's Epistles.
I don't know who do you think you are or who gave you the authority to judge who is a Jew and who is not. Essenes were Jews, Sadducees were Jews, Samaritans were Jews, Alexandrian Jews were Jews as far as I know. And so are Orthodox Jews, the Reformed and Conservative Jews...they all share one thing in common: they reject Jesus as the messiah. On everything else they differ.
Do I understand you to be claiming that the present day Jewish Canon (Torah) of the Orthodox and Reformed Jews is nothing but a surviving sect?
Rabbinic Judaism in all its forms is the sole survivor of the Pharisaical sect. The essense, and Sadducees did not make it. The only other survivors are a few hundred Samaritans who still practice Temple Judaism.
Romans 3: [1] Then what advantage has the Jew? Or what is the value of circumcision? [2] Much in every way. To begin with, the Jews are entrusted with the oracles of God.
And your point is?