If there is one thing that is clear int he israli-Palestinian conflict its that there ar eno good guys on either side with a gun. The only good guys in any of this are the massive number of Palestinian casualties and the small handful (comparably) of Israeli hostages..
Honestly I think that is being too generous.
#1 is valid, genocide wouldcause them to stop because ther eis no one left to kill.
#2 The very idea there is a hamas that can surrender is not really accurate in my mind. Even if the leader did surrender why would the masses of hamas, who are just citizens who had their families slaughtered, accept it? All that would happen is they would change their name or get a new leader. Hamas cant stand down because its own members never would because Pallestine is a country with millions of dead martyrs, youc ant reverse that.
#3 Israel still wouldnt stop short of being wiped out themselves. Even if the USA themselves said we would bomb them if they continue, they would continue.
#4 even that wont work unless 100% of Palestinians would be forced to leave israel all together.
Sadly I think there are one of two outcomes.. 1) (as you say) complete and utter genocide 2) if they were to stop (as they did in the past) it would only be so there are enough pissed off people left to fight them they can use that to sway public opinion to allow a genocide at all, which brings us back to #1
In fact I am of the opinion the only reason they let Palestine survive as long as they did is so someone would fight back enough to give them excuse to genocide them entirely and have some level of global acceptance.