Is it ever justifiable to target healthcare facilities during wartime? Why or why not?

No, not at all. Innocent lives may be cost due to the inhumanity and ignorance of one country by targeting medical facilities. Attacking them does not benefit the attack in many means, or weaken the victim side in any way. Innocent lives should never be cost in war, or any lives at all.

It's not justifiable for ANY side to target civilian targets of any sort. While Hamas' tactics are centered around asymmetric warfare, and blending in with civilian populations, the IDF needs to respond accordingly, and without targeting their own population with munitions.

Yes, because Hamas has centered their people under and around healthcare facilities. Israel warned Palestinian civilians to leave, and Israel has to put its own citizens' safety first. Because of that, terrorists cannot be allowed to have free reign right on Israel's borders. Israel is not attacking them for no reason.

Provide a on ground military operation and only aim for the enemies not just bomb hoping to kill enemies

Whether its justifiable or not is in the eyes of whoever did it, they probably thought it was justifiable. Heck, Hitler thought he was saving the world. War is the business of the collective of those who are in it, like all other examples of collective morality, it is a corruption of every moral system.

No because if you are targeting though's buildings when civilians are in there you are just killing innocent people who are most likely to afraid to join the Military.

If that is where the terrorists are hiding and endangering their own civilians then yes it is justifiable.

No, and I'm pretty sure that's legally a war crime

No because it’s a needed resource for the inhabitants