I think this is very good. The only thing I'd like to add at the moment is that it does have practical effects. I agree with Tim that most of us do value things that we can summarise as well-being, and that this extends to the well-being of others. But even among this "most of us" there will be differences in what we actually value - including what we classify as well-being (is it pleasure and other such feelings, living a life in which our actual preferences are largely satisfied, having the capability of acting in certain ways if we want to, actually living in certain ways, or what?). As a result, it's not surprising that there are intractable disagreements even among "most of us" about the form that morality should take (or, as it's usually seen, about what is really morally right and wrong). Fortunately, most of those disagreements are sufficiently marginal to allow a lot of convergence. Without it, day-to-day life would become a nightmare ... except that day-to-day life in human societies would not be possible at all.
My approach to difficult moral debates is to try to work out what values are stake - values that people actually have, rather than "objective values" - and what convergence seems possible if we engage in rational reflection. This may not seem like enough, but it's all we have. What's more, I suspect (though not in a position to prove this) that the world would function a lot better if we all thought like this, concentrated largely on finding the relevant non-moral facts, and abandoned ideas of some courses of action being absolutely, unconditionally required. Again, this is not how morality is generally thought of, but morality, as it is usually thought of, is an illusion.