Kant is not saying - about freedom or any other subject - anything of the form: "Not-p but we must assume that p." That's close to self-contradictory, like Moore's paradox: "p, but I don't believe that p".

I do not know how much my own work has achieved, and I must not pretend it has done more than it has.

Adam Smith saw the greed of modern capitalism for what it was - a form of destructive ambition that may have favorable effects on the productive capacities of society, but which is of no direct benefit to anyone - not even to the greedy themselves, whose illusory chase after a will-o-the-wisp leaves them morally bankrupt and unhappy.

Freedom is an unprovable but unavoidable presupposition, not an article of faith.

Kant says that we may regard ourselves as legislator of the moral law, and consider ourselves as its author, but not that we are legislators or authors of the law.

We can treat human responses to cognitions as involving law-like connections grounded on free choices which show themselves in our character.

It is rational to choose the right means to your ends to develop very elegant abstract formal theories of rational choice, and then turn these into what look like moral theories. Philosophers tend to be ravished by the formal beauty of such theories, and they don't pay much attention to the fact that our human limitations make them pretty useless in practice, while the simple point about instrumental reasoning is too shallow to be of much real moral interest.