Avira- Rav Kook doesn’t say it’s wrong to own a human being. To the contrary, he explains how being owned can be in a slaves best interest. Rav Hirsch is the one who seems to assume that it is better for there not to be slavery; it was only permitted for Jews to own if there was already slavery. I get the impression that Rav Hirsch is a person you are Machshiv.
I think we are mostly on the same page about this. I agree that that owning a human being is not “Lo Dibrah”, but some of the Halachos might be. I think it’s a very good thing that slavery in America was abolished, because it was done in a very cruel way, which was never permitted in the Torah. Instead of being enslaved by merciful, kindhearted masters, who would lead them in the way of the Torah, they were enslaved by vicious monsters who would beat them to the point of death.
Regarding Rav Kook and meat, i believe Rav Kook’s position was that in an ideal world, we should not be eating meat. In the current world, however, where there is so much cruelty against people, he felt that it’s ridiculous to stop eating meat. We have to focus on the big things, like human bloodshed, before focusing on the less important things. He felt, that at some point after Mashaich’s arrival, when the world would be so perfected, it would be proper to become vegetarian.