Kant's treatments of rational theology and metaphysics were aimed primarily at theoretical questions. His attitude toward the pseudo-sciences of "special metaphysics" in Wolff and Baumgarten was always double-edged. He did see them as pseudo-sciences but also valued their doctrinal value and especially their regulative value for the empirical sciences. Like his views about religion, I don't think any of this is any longer viable in its original form.
Kant's system of duties constitutes a Doctrine of Virtue because the duties also indicate what kinds of attitudes, dispositions and feelings are morally virtuous or vicious.
Our decisions need not be seen as resting on procedures that are merely instrumental in making judgments that are reliably truth-tracking. The procedures might be more directly related than that to truths about what is right or good, or about what we ought to do, or to principles that tell us what is true about these matters. And I have no metaphysical theory about the truth-conditions of such truths, except to say that as objective truths, they must be independent of the attitudes, decisions or actions that they are supposed to justify or for which they are to offer reasons.
