You say that Israel will have no choice but to implement the "two-state solution," allowing the "Palestinians" to have their own state alongside Israel. If not implemented, Israel will have to absorb the millions of "Palestinians," thus giving them the right to vote and be elected inside Israel itself. You say that any other alternative must be ruled out as unjust because it will leave the Palestinians with no right to vote and run for office, and you say the world will not tolerate a situation in which "Palestinians" are denied the right to vote. SO Israel either has to absorb them and allow them to vote in Israel or give them their own state where they will have the right to vote.
The problem with your suggestion is that "Palestinians" will still not have the right to vote even if they are granted their own state in your "two-state solution." If a situation must be ruled out as intolerable as long as it involves denial of a right to vote to "Palestinians," then you must rule out any "Palestinian state." Arabs do not have the right to vote in REAL elections, in fair and open elections, in any Arab country. The world has never had any problem tolerating that! Arabs CERTAINLY do not have such a right in Gaza's Hamastan, and any West Bank "state" would be no better. Sure, Arab regimes hold empty make-pretend for-show Potemkin "elections" but never real elections, Jimmy Carter's approval notwithstanding. So any implementation of your two-state "solution" would leave the "Palestinians" with no real right to vote and no real civic rights of citizenship in "Palestine."
Therefore if Israel refuses to grant the "Palestinians" Israeli citizenship, refuses to grant them the right to vote in Israel, and also refuses to allow them to have their own state, then just how are those "Palestinians" any WORSE off with regard to the right to vote and participate in civic society than they would be in any "Palestinian state"??