One thing is the dream of return, another altogether is what Zionism was at its founding, inspired as I said above in the idea of a nation for each "race", that term commonly used in Europe at the time for the "French race, German race" etc, along the lines of what we consider an ethnicity. So let's update to that term and observe that early Zionism, and that includes Ben-Gurion, was a movement much in emulation and in tune with its European times. It was not directly driven by adherence to mythical Judaism, and many arguments of that day had to do with that fact.
Not the same thing as Zionism. For example, some have argued that the return should coincide with the appearance of the Messiah; iow, at a time when YWH has indicated that it was the time. This is coherent if one goes by the Exodus myth, in which God was very choosey about the "when", that time being when the lessons of the wandering in the desert had been learned. Others have argued that the Diaspora must be taken as revelation, that God had new plans. This is in line with the flood and pilar of salt punishments as lessons. Zionism is an ethno-nationalist movement quite independent of religious teachings. I heartily recommend reading early works, or finding a link I have left to a video that goes through quotes and book references quite thoroughly. Jewish historians and philosophers document this history in their works. I'd provide the links, but I do not keep a collection in some war chest; for now, seek those posts that have them, mostly in my own thread, I believe.
Today that may be true. It most certainly was not at the time of the conquest and expulsion of the indigenous Palestinians, the point again being that the creation of the state of Israel was Zionist-nationalist in nature and not one of adherence to the faith, not that either justify the colonization. This does not mean there were not immigrants, especially later ones, that did.
It also remains to be the case that a non-Semite Jew, even a recent convert, may claim land in the West Bank by right of religion alone. This is grotesque, divorced as it is from all historical, biological or other rationales, making it purely a case of religious extremism a la ISIS.
ETA: Being a Semite or not is only germane in the sense of making the point that Palestinians are as much Semitic as anyone in the region, such that Semitism cannot be an argument in favor of one group having greater claim than another; i.e., the justifications used instead of ethnicity, given how problematic that would be for European Jews, are wholly parallel to those used by ISIS: religious canon supersedes all.