Finally an atheist proper, with views and questions

[Lucian]

I'm afraid you've lost me there.  Non cognitive utterances are those with no truth-aptness, and thus no way to be in error.  Subjective and relative utterances are emphatically not realist utterances.  Your listed justifications were not realist claims, but they simply are the justifications for noncognitive, subjective, and relative metaethical claims whether you view them as moral claims or not.  This is what I mean about a semantic argument.  You're not disagreeing or mounting an argument against the content, just a word.

Non-cognitive utterances are indeed not truth apt, but the claim that moral claims are intended to be non-cognitivist can be in error. 
I may misunderstand relativistic and subjectivistic views then, so thanks for pointing that out, still early days in my reading. I guess I was thinking of those as "there can be real moral values, just not globally binding". Will definitely need to do more reading and thinking on that - only been 3 or so weeks reading on this - The Stanford Encylopedia or Philosophy says on one page "Second, it is worth stating explicitly that moral anti-realism is not a form of moral relativism—or, perhaps more usefully noted: that moral relativism is not a form of moral anti-realism."Second, it is worth stating explicitly that moral anti-realism is not a form of moral relativism—or, perhaps more usefully noted: that moral relativism is not a form of moral anti-realism." https://plato.stanford.edu/entries/moral-anti-realism/

re "You're not disagreeing or mounting an argument against the content, just a word.", I agree that error theory is a semantic claim and I certainly didn't think my justifications were actually realist at all. I mean that I have reasons for doing things that I do not consider to be moral reasons in any sense. They are just reasons I want the way to be a certain way and for people to act a certain way. If they don't, I don't view them as immoral, or as bad, just as I don't see people as "good" if they do some things. At this point, I may well be slipping into non-cognitivism if I am not careful, but I am not sure I am.

The amoral view is also partially stemming from a lack of belief in free will (if defined as the ability to do otherwise), partially arising from reading Karofsky's A Case For Necessitarians https://www.routledge.com/A-Case-for-Nec...1032033174