I agree with most of your excellent post, but I see the particular point you make here a bit differently.
When confronted with closely related species and shown the degree of similarity, the creationist claim is that god/s reused a template they had already developed.
The quoted argument argument has a weakness common to nearly all arguments that "God would not have done it that way". In essence most (and probably all) such arguments are straw men because for the most part, the typical creationist does not, and more importantly,
need not make specific arguments about how God did it. Why should a creationist favor the idea that God had a wing template that he used whenever he wanted animals to fly, or an echolocation template for bats and dolphins? God is all powerful,with infinite resources at his command, and might use any route to make an animal fly.
Convergent evolution really does not disprove creation so much as c.e., and the evidence for convergent evolution do disarm one particular creationist arguments against evolution. Let's recall that the conclusion regarding evolution as being the theory of the origin of species is not a proof, but is instead arrived at in the same was as are other conclusions. Namely by a process of verification and falsification and not by eliminating of special creation and other explanations as a possibility. In fact such elimination is impossible on the scale necessary to constitute a proof.
Obviously, the evidence does rule out certain creationist paths, but not all. The fact that a particularly silly creationist argument is ruled on is of little consequence.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King
I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend. Thomas Jefferson
Seems to me if its clear that certain things that require ancient dates couldn't possibly be true, we are on our way to throwing out all those ancient dates on the basis of the actual evidence. -- Faith