What is central to morality is rational self-constraint (acting from duty), in cease where there is no other incentive to do your duty except that the moral law commands it.

Kant can provide, and has provided, a good model for philosophers to think about the relation of metaphysics to science and scientific methodology.

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.

Reason necessarily expresses itself through emotions and emotions are healthy only insofar as they are expressions of reason.

There is no author or legislator of the moral law. It is simply valid in itself in the nature or essence of things. We become autonomous only when we obey it, because then our will aligns itself with the objectively valid law, and our choice follows the same law as that we give ourselves. We can think of rational faculty (or the idea - the pure rational concept, not exhibitable in experience) as the legislator or author of the law because reason recognizes an objective standard, and to that extent is already aligned with objective moral truth.

Kant certainly was sympathetic with the metaphysical tradition of rational theology that he criticized.

One rational standard of action is how well it promotes the end it seeks. Another standard is whether it aims at ends which are good. Both of these, but especially the former, depend on judgments of fact.