The Khazar theory is controversial, unscientific, and has been exploited by anti-Semitic circles in the past. If you are repeating it here innocently, I suggest you read more about this topic from less subjective resources, i.e. non-Islamic material. Nor is there any real, scientific anthropological consensus that the majority of Israelis have Khazar ancestry. You are simply wrong.
The questions you have raised can be used to "refute" the legitimacy of any nation-state. There are no contemporary groups who claim to be the descendants of Canaanites, just like there are no contemporary groups who claim descent from the Etruscans. The closest example I can think of are the Samaritans, who still live in their lands unscathed.
To have a position be "exploited by anti-semeitic circles in the past", does not give said position any less credence. That said, I am willing to admit that any in-depth knowledge I have regarding the Khazaar Theory is scant at best. Perhaps you can point me to the direction of ubiased scholarly work that debunks the theory. And by unbiased, I mean work written by completley unpartisan athropologists/historians (if such a breed exist!)
At any rate, Jewish identity is much closely entwined to history/culture than ethnicity. Converts are fully accepted as Jews, so whether European Jews have distant Khazar or distant Hebrew ancestry is quite irrelevant. How many French citizens today have Frank blood, to begin with?
It is not as irrelevant as you think. One's ancesteral claim to a land - any land - is based on, well, one's acnestory. If the claimant doesnt have said ancestory, than his right of ownership diminishes significantly. If I tomorrow decide to convert to Judaism, do I now have ancesteral right to the land of Judea?
Wrong information again, Jews probably rose as a subculture in the greater whole of Canaan. Forget about the Exodus, the Egyptian slavery, etc. There has been a continuous Jewish presence in Israel for 2500+ years, despite great oscillations in population figures, including two great plummets, i.e. genocides carried out by Roman legions. Even when Arabs conquered Israel for the first time in 7th century, the majority of the population was Jewish.
Perhaps your grasp of history is better than mine, but I was of the opinion that Jewish presence in the holy land was, at the time of Muslim conquest, minimal and predominently Christian? I would assume as much considering the Levant region was controlled by the Byzantines at the time. Is any historical-census/anecdotal evidence to suggest that the region was largley Jewish?
It is an interesting idea that any Palestinians who happen to live in Israel today were the colonists of an earlier epoch. I will not even mention the great importance of Israel in Jewish thought and tradition, secular or otherwise. Jewish identity is half-crippled without access to Jerusalem.
Although the language of Arabic spread as far as the Levant, it does not neccesarily mean that their ancestors were the original colonisers from Hijaz. It just means that there ancestors adopted arab customs, religion and language. The "arabs" from palestine and Syria look very different from the "arabs" of Saudi Arabia. Perhaps these 2 sets of "arabs" dont have a shared ancestory? Perhaps the "arabs" of the Levant are descendents from that area's original inhabitants.
Nazi-Palestinian collaboration was, of course, much more complex than the singular views of a single Mufti, as you put it. I strongly agree that the collective punishment of any community or group is inherently immoral, but Palestinians have also carried out similar deeds when they had the opportunity.
Elaborate on the complexity por favor?
The Roman Empire tried to subjugate Israel and was partially successful. Later when the Judaeans revolted, they carried out genocidal campaigns. Their attempts at colonisation were all failures. Byzantinians governed the region, but never entered the gene pool, so to speak. The Babylonian Empire governed the region for a short period, and there were no Babylonian settlements in the area. In other words, Jews were the only significant, persistent, and long-lasting ethnic/religious group to inhabit the region which roughly corresponds to the frontiers of the State of Israel today.
Jewish presence was continuous - that I do not doubt. But you are overlooking the Jewish diaspora - and whether jews from elsewhere in the world (who form the majority of Israels present population) have more of a right to be there than Palestinians who lived there 50 years ago. Some of these Jewish communities were well established in an array of lands accross Europe, Asia and Africa - have had numerous "intrusions" into their gene pool. Should they have an automatic right to return based on loose DNA evidence and biblical prophecy?