In my view, there was a long period in which analytical philosophy had little to say about ethics. I think their intellectual tools did not do well with it, and analytical philosophy was above all about revolutionizing the philosophical tool box. It was more or less assumed that the Truth about ethics was some form of utilitarianism (perhaps because some consequentialist calculus looked to them like a respectable tool). Kantian ethics was then interpreted as a particularly odious version of the False - "deontology" - and treated with contempt.

As with many metaphysical and religious questions, Kant thinks they lie beyond our power to answer them. If you can't stand the frustration involved in accepting this, and insist on finding some more stable position which affords you peace of mind and intellectual self-complacency, then you will find Kant's position "problematic" in the sense that you can't bring yourself to accept it. You may try to kid yourself into accepting either some naturalistic deflationary answer to the problem or some dishonest supernaturalist answer.

Smith could not be expected to have anticipated the horrors that were to come. But even in his own time, he was a defender of certain state actions that he thought necessary in order to safeguard the good effects of commercial society (Smith did not speak of 'capitalism' and was acquainted only with an early undeveloped form of it). Among these state actions the chief was general public education.

That Hegel's theory is derivative from Fichte's does not prevent it from being strikingly original and of independent value.

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

Fichte is concerned with freedom as non-domination.

In fact, if you read what Kant has to say about feeling, desire and emotion, you see that he is not at all hostile to these. He is suspicious of them insofar as they represent the corruption of social life (here he follows Rousseau), but he also thinks a variety of feelings (including respect and love of humanity) arise directly from reason - there is, in other words, no daylight between the heart and the head regarding such feelings.