Murder is not just worse than manslaughter it is on a different level.
Western criminal codes generally allow for no punishment, perhaps even no guilt, for a manslaughter. If Israel could remove Hamas without injuring any non-combatants I think they would. It makes a difference. Almost by definition suggesting that scale is a factor is implying that collective punishment is acceptable.
Criminal punishments are more about the social consequences than about the crime itself. If someone gets X years in prison for crime A and another person gets 2X years for crime B, it doesn't mean that crime B was twice as bad. It only means that after taking a large number of factors into account, it made sense to give twice as long sentence for crime B.
Surely you jest. How is this attack supposed to remove Hamas? It seems designed to strengthen Hamas, just as Israel has been supporting Hamas since their formation.
The existence of Hamas prevents a united Palestinian people while simultaneously giving Israel the excuse to reject a 2-state solution. If Hamas didn't exist, Israel would have to create a Hamas from scratch.
This attack is supposed to remove Hamas by killing them, or forcing them to surrender. There's a lot of legit criticism of what Israel is doing, but if you think it's designed to bolster Hamas, then you're really misunderstanding what's happening.
My point is that Palestinians have their share of blame.
Parent comment blamed everything on israel when clearly Palestinians have a fair share of blame - you can't deny that.
They can be stopped by arresting/killing the members. Why wouldn't it be possible? Similar groups have been stopped.