Without commenting on whether this presentation matches the original metaethics sequence (with which I disagree), this summary argument seems both unsupported and unfalsifiable.
Would this be an accurate summary of what you think is the meta-ethics sequence? I feel that you captured the important bits but I also feel that we disagree on some aspects:
V(Elves, ) = Christmas spirity
V(Pebblesorters, ) = primality
V(Humans, _ ) = morality
If V(Humans, Alice) =/= V(Humans, ) that doesn't make morality subjective, it is rather i...
Unpacking "should" as " morally obligated to" is potentially helpful, so inasmuch as you can give separate accounts of "moral" and "obligatory".
The elves are not moral. Not just because I, and humans like me happen to disagree with them, no, certainly not. The elves aren’t even trying to be moral. They don’t even claim to be moral. They don’t care about morality. They care about “The Christmas Spirit,” which is about eggnog and stuff
That doesn't generalise to the point that non humans have no morality. You have m...
Morality binds and blinds. People derive moral claims from emotional and intuitive notions. It can feel good and moral to do amoral things. Objective morality has to be tied to evidence what really is human wellbeing; not to moral intuitions that are adaptions to the benefit of ones ingroup; or post hoc thought experiments about knowledge.
"words should be used in such a way to maximize their usefulness in carving reality"
That does not mean that we should not use general words, but that we should have both general words and specific words. That is why it is right to speak of morality in general, and human morality in particular.
As I stated in other replies, it is not true that this disagreement is only about words. In general, when people disagree about how words should be used, that is because they disagree about what should be done. Because when you use words differently, you are likely to end up doing different things. And I gave concrete places where I disagree with Eliezer about what should be done, ways that correspond to how I disagree with him about morality.
In general I would describe the disagreement in the following way, although I agree that he would not accept this characterization: Eliezer believes that human values are intrinsically arbitrary. We just happen to value a certain set of things, and we might have happened to value some other random set. In whatever situation we found ourselves, we would have called those things "right," and that would have been a name for the concrete values we had.
In contrast, I think that we value the things that are good for us. What is "good for us" is not arbitrary, but an objective fact about relationships between human nature and the world. Now there might well be other rational creatures and they might value other things. That will be because other things are good for them.
But not everything people value is actually good for them. You are retaining the problem of equating morality with values.