PRO

CONS

Judaism

Had "wrong" form of Judaism

ECJ was pre-Talmudic in some ways

Had no "mikvot"

Polygamy

Believed in spirits

But this was Mesopotamian beliefs, not local Caucasian

They believed in talismans and amulets as protection against evil spirits and demons

Same goes in modern Israel

Absence of Kohanim

This might be explained, by this that ECJ got surnames relatively late, but there are Leviim (or at least people with ancestral name Levi or surname Leviev)

"Unlike all Jews, who pray towards east, they prayed toward west"

Synagogues face west, while real direction to Jerusalem is south-west - evidence of migration from Babylonia or South Persia

Customs

"hakhnasat orkhim" (hospitality)

Like Khazars, carried weapons (daggers)

Who said Israelites weren’t good warriors?

Blood vengeance

Also ancient Israelite tradition: check about "'arey miklat" - "Cities of Shelter" in Torah

Geography

Close to the Khazaria

But also close to the ancient Israelite Diaspora locations, such as Armenia, Media, Babylon, Persia and Crimea

Caspian Sea called "Khazar" in Azeri language

Onomastics

ECJ use holidays and blessings as names, example: Pisakh, Khanuka, Purim, Mazaltu, Simandu [2,3]

ECJ use some names known from Khazarian correspondence, like Nissi, Sinai, Serakh and Savriil [2,3]

Some ECJ have Turkic surnames

Unlike Jewish Khazars the ECJ not only used names of the brightest biblical characters but also names considerably less bright. To be more precise, ECJ used ALL sorts of very ancient Jewish names! [2]

Linguistics

ECJ speak Juwuri/Juhuri ("Jewish") - South-West Middle Persian dialect, this is the strong evidence, that their ancestors migrated from the areas of South-West Persia or Babylonia in the time of Sassanids

Juwuri have Semitic (Hebrew/Aramaic/Arabic) elements on all linguistic levels. [5]

Juwuri have many Turkic words, so probably it's Khazarian language relexified into South-West Iranic and Hebrew

The Turkic words in Juwuri are loan words from Oghuz and Pronto-Caspian Turkic language families, not from Bulgarian.

Juwuri is related to language of Caucasian Persians (Farsi or Paran), so probably they are one ethnic group - Tats, divided into different confessions

There is no full intelligibility between speakers of Juwuri and Paran (Tat). And except language there are no other common parameters between these groups.

Genetics

Majority of ECJ genetic paternal (Y chromosomal) haplotypes shared with other Jewish communities and consistent with a Mediterranean origin [4]