the problem with de-evolution
If the inhumi all refuse to feast on human blood since they become "good" from good humans, then their offspring would return to mindless animals. There is nothing to prevent the mindless animals that are the children of good inhumi from sucking off of the people, especially with a colony of humans on Green. They would have no scruples, then their children would be intelligent. It would just be a threat to humans with alternating generations of inhumi. I don't like this golden rule idea.
*This is WHORL, for discussion of Gene Wolfe's Book of the Long Sun.