On the subject of cannibalism: I think that cannibalism, in and of itself, is thoroughly a moral non-issue. It is in and of itself neither good nor bad. I don't see any intrinsic horror in either the idea or the act of a human being consuming the flesh of another.
Remember the 1973 science-fiction film Soylent Green, starring Charlton Heston? The great horrific revelation at the end was that the staple food of the desperately overpopulated, polluted future, Soylent Green, was produced from the bodies of deceased humanity. I never saw any reason to be disturbed by this, as long as those who had died had not met their ends unwillingly. Also, the consumers of Soylent Green should have been informed of the product's origins--transparency in commerce, politics, and interpersonal relations is a great ideal of mine.
Many of the horror stories involving cannibalism, whether real or imagined, revolve around people being murdered and then having their flesh consumed, with the killing sometimes being motivated by the desire for the flesh itself, or the flesh being consumed as a corollary/side effect of the killing. Murder is very unethical, and merits the utmost serious attention from any society claiming to be civilized. I find murder horrific, and have been horrified by the cannibalistic elements that are involved in some murder cases, but this has been because of the murderous impulses behind the act, not because of any intrinsic horror in the cannibalistic act itself.
There are nuances and degrees to this issue, as with most everything. I am certainly against corpses being desecrated for acquisition of their flesh, without the approval of the deceased and/or their remaining loved ones. I would be against anyone being forced to consume human flesh, or being deceived into eating human flesh, without realizing what they were doing. Finally, it is worth remembering that Christian communion is at the very least a kind of symbolic ritual cannibalism--if one follows orthodox doctrine, with belief in the transubstantiation of bread and wine into the actual body and blood of Christ, it becomes a literal act of cannibalism. And I see absolutely nothing repugnant in this.