Kant did think he had a moral route back to rational faith in God, for those who need it, and he thought that at some level, we all do need something like it.

Kant's description of most ethical duties reads more like a description of moral virtues and vices. Once we see this, we see that Kantian ethics is indeed a kind of virtue ethics, and that it does not "divide the heart from the head" (to anticipate one of your later questions) but instead recognizes the deep truth that reason and emotion are not opposites.

Until I was a junior in high school, I was a "boy scientist" type and expected to go into chemistry. Then I discovered the humanities. I read the plays of Shakespeare voraciously, some novels, such as Pasternack's Dr. Zhivago and Sinclair Lewis' Main Street, and I got into philosophy by reading Kierkegaard and Nietzsche.

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.

Leaders of nations, and people whose wealth or fame gives them power over the lives of others quite often do more harm than good.

I think that both Mill and Sidgwick are great and admirable philosophers, from whom we still have a lot to learn. I would not favor a form of Kantianism (if there is such a form) that treats Mill's or Sidgwick's moral philosophy with disrespect.

The species of anti-Enlightenment religion we find among evangelical protestants is far more impoverished, anti-intellectual and downright wretched.