There are are two fundamental concepts that impact decision making processes in time of war: necessity and proportionality. Neither is taken into consideration by the authors: their argumentation is purely theoretical and is based on the conceptual interpretations of the selective issues they raise, completely ignoring the realities of the situation they are commenting on, the realities that they don't appear to be fully aware of.
The lives of civilians in Gaza are endangered, even in relative peace, by the presence of heavily armed combatants mixed into the general population. It is ridiculous to argue that Israel has any control over this overarching fact. It is equally ridiculous to assume that this situation is desired by the civilians in Gaza.
In time of war, when Israel's right to self defense is an indisputable justification for military action, Israel cannot order, demand, or politely suggest, that Hamas militants vacate civilian ares. Since Hamas policy and practice is to deliberately hide among civilians, no cooperation from Hamas to protect their population from harm is expected.
This is where necessity and proportionality come into place. It is obvious that it is absolutely necessary to remove the civilians from the areas of military actions. Proportionally, how many civilians will risk death by staying versus how many civilians will risk death by leaving? The answer is beyond obvious. Since Israel cannot effectively supervise the orderly evacuation of the Gazans from what Hamas determined to be a war zone, the only option left for Israel is to advise the civilians and suggest a course of action for evacuation, and warn them of consequences if they choose to stay.
Likewise, it is beyond any question that Israel cannot, or is not solely responsible for providing humanitarian aid to the evacuees. This is a matter of negotiation between multiple parties, and ALL of them are equally accountable for delivering humanitarian aid.
This is the absolute best Israel can do under the circumstances, which they did not themselves create or impose on the Gaza civilians. Accusing Israel rather than Hamas of violating international law is pure bullshit.