How to go about re-integrating these people into the global population? Assuming the Palestinians want their land back, then they'll switch places with the refugee camps? Or go back to western europe.
A large portion of "Israeli" Jews (a majority, I think) are not Ashkenazim. Most of these are descendants of Sephardi who would no longer be welcome in the countries they left (mostly because of the existence of "Israel"). A large amount of the Jewish migration into "Israel" is a tragedy that can't be undone, at least in the short term. I think it's likely that if apartheid were ended, many would voluntarily choose to leave to a 3rd state, but the likelihood of Europe and America accepting a large amount of Arab Jews in this situation seems very low to me.
Many cite the South African example, but the "Israeli" government and people are (as far as I know) criminal at a rate and to a degree that far exceed even Afrikaners. I really don't see how many of them will live with Palestinians in peace, but I hope it's possible. I know with 100% certainty that any problems and violence after the end of apartheid would be coming primarily from "Israelis".