Sorry I'm coming to this post so late after it was published...
Concerning your thoughts about the moral argument: This means that there is no inherent transcending "value" in anything? The life of a 3 year old child is ultimately no more valuable than fecal matter. If my daughter is raped and killed, I can find solace and comfort in knowing that my feelings are social constructs. I should just fuhgedaboudit.
I admit, I am referring to emotionally charged situations because I am programmed to. It just seems to me that if I believed this way that you describe, no objective morality, that since there is no value in anything, I would live for my own personal gratification only. Squeeze all the pleasure I can out of life and go out with a bang. Nothing we do matters except for a short period of insignificant time on this planet. That means rape, steal, kill, lie, cheat, if it makes me happy in any given moment. Nike: Just do it. Know the consequences and risks to future pleasure potential, but just do whatever you want. Sure, people will be hurt in the process, but none of that matters in time. All that matters is me and my pleasure.
Is this consistent with your position?