Consequentialist theories pretend that we can set some great big ends (the general happiness, human flourishing), provide ourselves with definite enough conceptions of them to make them the objects of instrumental reasoning, and then obtain enough reliable information about what actions will best promote them that we could regulate our conduct by these considerations alone.

It is probably not a good idea to ask someone to expound a position they do not accept and do not feel they even fully understand.

The problem is that many who reject Marx do not read him, or read him only by bringing prejudices to their reading that prevent them from understanding him.

The problem I see with utilitarianism, or any form of consequentialism, is not that it gets the wrong answers to moral questions. I think just about any moral theory, worked out intelligently, and applied with good judgment, would get just about the same results as any other.

It would be nice, wouldn't it? if we could get comfortable about the problem of freedom. Kant thinks that we can't.

I think the term "Kantian constructivism" as an oxymoron. Kant was a constructivist about mathematics, but not about ethics.

Kant does not think there is anything wrong with being beneficent from sympathy. He thinks we have a duty to cultivate sympathetic feelings by participating in the situations of others and acquiring an understanding of them. He thinks we also have a duty to make ourselves into the kind of person for whom the recognition that something is our duty would be a sufficient incentive to do it (if no other incentives were available to us). That's what he means by "the duty to act from the motive of duty".