Remsen can fact-check me here, but I believe being a Jew is a religion, not a nationality. So, one cannot be "part jew".
You can be either. Others have already detailed the conversion process in becoming a Jew as far as religion. Anybody who is a physical descendant of Abraham is some part "Jewish" unless you discount Judaism by birth. Israel is a nation but it is also referred to as a people. ie the descendants of Abraham. Lots of people are "part Jew" and don't even know it.
As to their religion...I have no idea. Being a Christian isn't predicated on what anybody else says or thinks other than God Himself and you, the adherent. Maybe the Jews have a say in who is and who isn't.
Are there non-Jews in Israel?
Actually, I've read that there are more Palestinians in Israel than Jewish people...from several sources, but that needs a fact check from a reliable source...fact check before posting states 21% and most are Muslims... interesting read & site:
https://www.jewishvirtuallibrary.org/the-status-of-arabs-in-israelI do know there are more Jewish people in NY State than in Israel....
Israel and Mexico are the two countries I think that allow you to have citizenship of their country and another one...
I've had acquaintances, who were American Jews, yet they went and got Israeli citizenship.
without living in Israel...
I don't think there are more Palestinian Arabs in Israel (current borders) than Palestinian Jews, but again, it is a matter of how you use a term. The term "Palestinian" is now used to mean only Palestinian Arabs, but before 1948 it was also the term used for Jews who lived in the land. But if we're talking about Israel under internationally recognized borders, it's a majority Jewish country.
I claimed Israeli citizenship when I joined the military back in the 1980s, and at that time you definitely had to be in Israel, pay taxes there, have an address there, etc. to get citizenship (though, as a Jew, you also would have the absolute right to claim citizenship, so long as you did physically reside, pay taxes, etc. there...i.e., there was no need to do anything other than show up, prove that you're Jewish and then ask for citizenship). But as far as I know, you can't become a citizen without actually moving to the land.
