Anyway, you bring up an interesting point Muman, and I would say I don't agree.
My rabbi has taught me that there is such a thing as an inherent sense of morality, and a person can at times trust that, and indeed those rabbinical sources who suggest that the Noahide laws should be known to/derived by any person even without ever seeing the Torah, would have to agree with this. There are rishonim who say that the goyim should know or figure out the noahide laws.
I don't understand what point you say I am bringing up.
There is always the command to not stand idle as your brother bleeds, and that when one does nothing he thus accepts or condones the evil. This is one reason Schem was destroyed, and I understand this lesson.
But the case of Pinchas was a case of Halacha which Moses appeared to forget and Pinchas, who remembered the Halacha was the only one who could carry it out, and this is why what he did was so meritorious.
But regarding Essau and Hushim, all i know is this one story about how Essaus head was removed in this incident. No doubt Essau was a wicked man, and he was a rodef who wanted to kill Jacob, thus he may have deserved the death.
If you could point to a good source which explains this I will investigate it.