With regards to the Israeli left being too pro-2 state, I've had this discussion before on here. I just don't believe it. Certainly many young activists on the left are open to a single, non-Jewish state. Even among the establishment politicians of the centre-left, I think many have secretly made peace with the idea. Publicly they are very strong for 2 states though because they are worried about being painted as traitors or unpatriotic. It's simply overcompensation. The same reason they call their party "Zionist Union". It reminds me of how American Democrats backed the Iraq War and opposed gay marriage to prove they weren't dangerous radicals but as soon as the political winds become more favorable, they revealed their real positions.
With regards to Gaza, I'm even more sure you are wrong there. Egypt will not take it. It might become independent for an interim period but as soon as tensions with Israel ease (which is likely if West Bank Arabs are given citizenship), immigration and cross border trade will dramatically increase. Israel and Gaza will become economically entwined in such a way that unification will become inevitable (especially if the Israeli Arabs continually campaign for it).
As an Israeli center-leftist who knows many like me, I have to disagree. The left will never support a unified state with two official nationalities (Jewish and Palestinian) because it would mean the complete destruction of the zionist dream. I firmly believe that the only way for zionism and Israel to survive is a two-state solution, and I want to believe that Israelis and Palestinians will slowly realize it too. The survival of Israel as a
Democratic, Jewish state is vital for all Jews worldwide.