Gnostic slope? Not really. Gnostics generally separated the ideas of soul/body before death; I separate the ideas only after death. Reversing their marriage, perhaps death makes the one become two? PS: αδελφοι in Rm.12 really does cover sisters as well: Paul was not sexist.Careful, you're crossing into Gnostic territory. On the contrary:
Rom 12:1 I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship.
1Co 6:19 Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own,
1Co 6:20 for you were bought with a price. So glorify God in your body.
Your reasoning is not sound.
"Using a particular, Paul examined the idea of an act (eg human carnivorism: Rm.14:2) being sinless objectively, but sinful subjectively, and having shown that conscience can be wrong, he rounded off with a warning that whoever opposes their conscience, subjectively sins. What seems wrong (or right) to one person, might not in itself be wrong (or right)."
"Biblically, God more than allows human carnivorianism, BTW (Ac.11:7—kill and eat: global abolition of symbolic unkosherism)."
Both those quotes are begging the question. Again, humans are created in the image of God, and I would argue that that includes our bodies, and were never given as food, unlike plants and animals. And, again, cannibalism was a horrible curse brought on those under the most severe judgement for sin.
Yes, it is objectively sinful and an abomination.
Dealing with animals and what parts to eat or not eat is a matter of taste. Cannibalism is not.
Does the imago include biological bodies? We agree that human beings are imagodei. But God does not have a biological body, so biology is not as such included in the image, is it? Per Scripture, cannibalism could result from grave sin, but was not said to be sinful per se or to be punished as such. God’s curse was bringing them to such a state that they even ate their children. But it presumes that his people would have already violated the unkosher-meat ban (eg pig). Should we say that eating pig (once a result of grave sin) and eating human (once a result of grave sin), are in themselves, sinful? Both would have been unkosher under Sinai. I do not see that biblically human flesh was ever globally ruled out, even if not specifically ruled in by the generality of meat & veg.
You asserted: “it is objectively sinful and an abomination.” You might be right, but I do not see your proof/cogent-reasoning.
You said that cannibalism is not a matter of taste. I suspect that both actually can be distasteful. I think that you meant that cannibalism is more than mere distaste, not that the greater (sin?) excludes the lesser (taste).
Anyway, time to close down for the evening.