I'm not sure if it's relevant to put forth here, but the entire time I was reading this (almost) it kept rolling through my head what Carl Sagan once said, in that we are made of the stuff of stars; essentially that what constitutes our physical forms is inherently indistinguishable from most of what constitutes the rest of the universe. Thus, the physical laws which govern the universe govern us in all ways.
And since it's been demonstrated scientifically that no one single model of what we would define as 'natural law' can explain all things (specifically that certain physics models break down at the event horizon of a black hole, but also that the rules which govern the subatomic don't exactly apply to the universe above the subatomic) it stands to reason that what we construct as sound moral arguments in our mind, itself a construct of the physical brain, wont always be applicable in all ways.
Hence it might be true what the bible says in Ecclesiastes - to everything there is a season. To whit, there is a time when suffering is good and there is a time when suffering is bad. There is a time when pleasure is good and there is a time when pleasure is bad.
That may sound like I'm arguing for Relativism as an approach to moral argument, but relativism is a form of an absolute and I don't think we can rely on the human construct of Absolutism to determine pure morality. There is a time for Relativism and a time for Objectivism and the key as I see it is knowing when to apply, both ethically and with supreme equity, these concepts to the questions of morality within the human condition.
To my mind, one of the ways to go about that is to not rely on intention as a primary measure of the morality of harm, but rather the harm itself should be the barometer in determining if an action is moral or immoral. For example, one consenting adult spanking another consenting adult is fine within the bounds of a mutually agreeable BDSM relationship. There is a mutual consent decree and therefore the pain of spanking is not harmful as long as the bounds of safety are respected. However, a parent spanking a child as a corrective measure is not fine because there is no inherent consent decree within the bounds of that relationship to say that the child agrees with being subjected to corporal punishment. The child is forced to submit to the whims of the parent because the child can not survive without the aid of the parent in the early stages of life.
Anyway, that's my contribution to this discussion. I look forward to what you, as the author of this essay, have to offer in return.