Concerning an organic (ie. "legal") establishment of Jewish presense in Palestine as opposed to expropriation (ie. "illegal"), there was some of that in the years before WWII and after. I've read a figure that 6% of Palestine was owned by Jews just prior to 1948. Some currents in Zionism was for this approach, others weren't. History has shown who prevailed in that one.
Lets say that Israel was established through legal transfer instead of seizure. Even before 1948 the problem of Jewish landowners pushing Arab peasants off the land became so acute that a rebellion occurred in 1936. The British colonial authorities curtailed Zionist land purchase at that point. I don't know if the process of pushing the Arabs out had been more gradual would have prevented the conflict that arose out of that situation.
Even the labor Zionists who favored rapprochment with the Palestinians (at least before 1948) operated from the viewpoint that "this land is ours and you are the interloper," so really what's the difference?