When you say the horn is not a gift, what am I to infer? That God is superfluous?
If existence is an impersonal mechanism which does nothing but cycle naturally to no purpose, yet Roland, as a human, is able by act of will to improve himself, thus turning it into a spiral, then the same questions remain: Does that spiral have a top? Can he ever reach it? What would he find at that point? Can he ascend all the way to Godhood?
If Roland on his own gives meaning to his universe, then what is the significance of this fact? Is a spiral that goes nowhere really any different from a loop? If the order of the multiverse which Roland seeks in the Dark Tower is in fact created by the very act of someone like him looking for it, does this imply that objective answers are illusionary? Should he ever reach the point that he is able to decide that in fact he is just chasing the wind, then he could, I guess, break away to freedom, as you say. However, would such freedom be worth having? Isn't that analogous to returning to the chaos of the prim?
If any of these are the fundamental condition of reality, then is trying to simply get whatever enjoyment the absurdity of nature might provide the best that man can hope for? In that case, I would personally prefer oblivion. (If oblivion were possible.)