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

Teaching and writing about philosophy is about the only thing I've ever been really good at.

Popular religion since the time of Kant and Fichte has gone in a direction they tried to prevent and that has been disastrous for the humanity both of believers and of the rest of us. Look at the role of religion in Republican presidential primaries if you need any confirmation of this last statement.

Kant takes a free will to be a being or substance with the power to cause a state of the world (or a whole series of such states) spontaneously or from itself.

Fichte thinks that the mutual recognition of one another as free beings belongs among the transcendental conditions of self-consciousness itself.

We can make mistakes about what we ought to do, and these are not the same as making bad decisions about what to do.

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.