With regard to #5, I've already discoursed somewhat on this in an earlier posting: "The Zionist movement successfully remade the Jewish people as a nation in the land of Israel. It took a series of scattered religious and ethnic communities and – with the ‘help’ of pervasive and (eventually) genocidal antisemitism – gathered them up and transformed them. ...”For me, personally, it's meaningful that we Jews have always understood ourselves as a people, well before the advent of nationalism. I've seen that denied too many times. The attempt among some Reform Jews to recast Jewishness as just Judaism, should be understood as assimilation in a colonial context. But it's particularly galling that those who deny Jewish national identities insist on a Palestinian national identity that is somehow "authentic." Jews, it seems, are just inauthentic.
Prof. Sand admits that there is such a thing as "Jewish identity," apart from the religion. But he doesn't seem to understand that all national identities are "invented." I blogged on this as well: "This is one of the lessons I drew from an insightful book by Prof. Rashid Khalidi: Palestinian Identity: The Construction of Modern National Consciousness (Columbia University Press, 1997). He makes the point that 'National identity is constructed; it is not an essential, transcendent given....' Khalidi proceeds to relate how Palestinians didn't see themselves as a distinct people until well into the 20th century. Just as anti-Zionist writers and activists would never think of denying Palestinians their understanding of themselves as a people, they should not be denying the Jews their sense of peoplehood – a consciousness born of centuries of persecution, discrimination and worse, not to mention strong religious and cultural continuities."
Early Reform Judaism, born in 19th century Germany and the US, attempted to recast Jewish self-definition into only a religious frame; classical Reform Jews were Americans or Germans of the "Mosaic" faith. The traditional or Orthodox view of Jews is of "Ahm Yisrael" -- the people or nation of Israel (even among anti-Zionist Orthodox Jews). The left has generally granted people the right to define themselves, to "national self-determination"; only with regard to the Jews does this seem not to be the case.
Btw, the ideas that Ashkenazi Jews are descendents of the Khazars and that Jews are more converts than descendents of the original Jews both strike me as not only politically irrelevant but also as likely false. Of course, as Seliger writes, such a discussion in a genuinely scholarly environment wouldn't be open to the same kinds of criticism whether right or wrong. However, some classically antisemitic motifs can be understood as inauthenticity -See Occidentalism for numerous examples- and I wonder if these notions of Jewish ancestry stem from a general view of Jews as inauthentic.