Your post amounts to:
Principle #1 -- If you are attacked you are an idiot not to shoot back.
Principle #2 -- Only direct threats to your life permit lethal force.
Principle #3 -- Israel has a policy of shooting all Palestinians based solely on their "Palestinianness".
I agree with your Principle #1. It is the foundation of the moral and legal idea of self-defense. If someone attacks you, you are an idiot not to shoot back. So the dispute we would have is whether or not Israel is "really" being attacked.
You are not being attacked if no one is hurt, injured or killed. You are not being attacked if your border fence is on someone else's property. You are not being attacked, if you have a buffer zone that is on someone else's property. Burning a tire, is not an attack. A peaceful protest, is not an attack. Throwing a rock, is not a threat to your life, or your fence.
Snipers shooting people in cold blood, is an attack. Drones dropping fire bombs on tents, is an attack. Shooting tear gas at babies, is an attack. Shooting people fishing and farming, is an attack. Collectively punishing 1.5 million people, is an attack.
I agree somewhat less in your Principle #2. I believe it is permissible to use force to protect not only direct, immediate threats to one's own life, but also to protect and defend other's lives and against threats to other's lives. So the dispute we would have is whether there is a credible threat to Israeli lives.
Wrong! It has to be an imminent threat to your life, before deadly force is permissible. Making up bullshit reasons to kill people, is just pure evil. You make such a fine German.
There is also the argument that it is legally and morally permissible to defend one's sovereign territory from an invader. You seem to believe that Gaza has every right to not only defend itself from an invader ("occupier"). Israel should have the same rights, but you persist in saying that "occupiers" have no right to defend themselves. Which is bullshit.
You are not defending yourself when you occupy someone else's property. You are initiating the violence.
Your Principle #3 is just an immoral demonization of Israel. And a blatant rejection of reality. Israel has done an exceptional job of being extremely precise (not perfect) of only killing those who pose an immediate threat to life or to sovereignty.
Is a guy in a wheel chair a threat to your life, or Israeli sovereignty? Is an 8 month old baby, a threat to your life, or Israeli sovereignty? Is someone fishing or farming, a threat to your life, or Israeli sovereignty?