Answer:
Is morality merely a social construct or something more
Morality is absolute. Ethics are social constructs (and this includes everything described in the question details).
I will defer to the ancient wisdom of Mencius (Confucius' disciple) to explain what is morality:
Everyone has a heart that is sensitive to the sufferings of others. The great kings of the past had this sort of sensitive heart and thus adopted compassionate policies. Bringing order to the realm is as easy as moving an object in your palm when you have a sensitive heart and put into practice compassionate policies.
Let me give an example of what I mean when I say everyone has a heart that is sensitive to the sufferings of others.
Anyone today who suddenly saw a baby about to fall into a well would feel alarmed and concerned. It would not be because he wanted to improve his relations with the child's parents, nor because he wanted a good reputation among his friends and neighbors, nor because he disliked hearing the child cry.
From this it follows that anyone who lacks feelings of commiseration, shame, and courtesy or a sense of right and wrong is not a human being. From the feeling of commiseration benevolence grows; from the feeling of shame righteousness grows; from the feeling of courtesy ritual grows; from a sense of right and wrong wisdom grows. People have these four germs, just as they have four limbs For someone with these four potentials to claim incompetence is to cripple himself; to say his ruler is incapable of them is to cripple his ruler. Those who know how to develop the four potentials within themselves will take off like a fire or burst forth like a spring. Those who can fully develop them can protect the entire land while those unable to develop them cannot even take care of their parents.