As you say, Darwin's theory of evolution is incomplete. To me it is akin to Newton's classical physics which although useful, fails at the large scales (relativity) and the small scales (quantum mechanics.)
It is also not metaphysics, philosophy or theology and every attempt to appropriate the theory for such purposes reflects poorly on all the related disciplines of science.
Are you admitting that the theory of evolution is "not metaphysics, philosophy or theology?"
I agree.
But then you say, "every attempt to appropriate the theory for such purposes reflects poorly on all the related disciplines of science."
I disagree.
Rather, it reflects poorly on metaphysics, philosophy and theology, not on science.
Real science parted from "metaphysics, philosophy and theology" a couple of centuries ago, although the latter are still crying, "Listen to us! We were here first!"
This is a great analogy, Alamo-Girl! Classical physics is thought to be (certainly by Niels Bohr) a special, "limited case" of a more general, comprehensive theory, quantum theory. Newtonian mechanics "works" perfectly well in our ordinary experience, which is confined to a certain range of scales and velocities that are . Yet we know that what appear as bodies in classical physics at the quantum level are not simple "bodies" as all. Also classical physics is predicated on a certain notion of determinism, which the quantum theory shows is not the actual case at all, that uncertainty is built into the very base of the system (so to speak).
Not to say that classical mechanics has at all been obviated by quantum theory: It is eminently valuable in making descriptions/predictions within the range of "normal" scales where the effects of the quantum of action are too small to notice, and where velocities do not approach the level where relativistic effects begin to kick in. Still the "Newtonian universe" fits into a wider, more comprehensive descriptive framework that includes both quantum and relativistic effects.
Thank you so much for your excellent observations!