Yeah, no. The kagan and some of the aristocracy. Perhaps 50 families or so.

The file and rank Jews in Khazaria were Jews fleeing from Byzantium.

The Khagan converted because for he thought it would be a good idea to have his own Abrahamic religion, since he was the peer of both the emperor and the caliph, and felt it unacceptable to be their underling in case of conversion, for both Christianity and Islam expanded aggressively into his khaganate.

For the Jews it meant security.

Sure but that was mean

Dont care Im jewish now

They weren’t fleeing, there was a Jewish community in crimea since antiquity involved in trade. If I remember stuff from uni properly there are documents from the Cairo genizah mentioning the Jews of crimea as late as the 10th c.

From the khazars’ point of view, the caliphate was an enemy and becoming Christian would have meant accepting at least nominal Byzantine suzerainty. Engagement with the Jews granted access to Mediterranean trade networks and also probably conferred certain privileges on the Jewish merchants in terms of the trade in furs, amber and probably most importantly slaves. Control of this trade was the basis for later development conflicts with the rus, who also trafficked in slaves

Also how large or extended or whatever was a khazarian aristocratic family? Could have been a few thousand people, even. I remember reading that Seljuq’s sons had names like Moses, Israel and iirc Daniel, it’s possible if not probable that the royal family of the Seljuqs were Jews before they were Muslims