The fallacy of affirming the consequent.
"And it is testable: Any number of potential fossil discoveries or discoveries from DNA could disprove the theory."
Uh no. Out-of-order fossils are attributed to 'fossil reworking' and ancient DNA is assumed to have survived millions of years through unknown processes based on the 'a priori' assumption of millions of years. This is also known as the fallacy of cherry picking for appealing to unobserved evidence against the theory even as all evidence falsifying the theory is explained-away. Such a 'theory' is impossible to falsify since it is a philosophy, not a theory.
"—True, the theory of evolution can’t be tested by how life began, because the theory isn’t dependent on how life began – whether life through divine creation, as the quote you gave mentions, or spontaneous generation, or abiogenesis, or aliens, or smurfs, it doesn’t affect the theory."
Again, Darwin merely used Hegelian dialectic to synthesize the incompatible pagan beliefs of spontaneous generation of life (e.g., maggots from carcasses and rats from garbage) and the Judeo-Christian belief in a Creator into a 'theory' that contained elements of both. Creation of 'simple' life forms and spontaneous generation of all subsequent life forms from those.
The theory is unaffected because it is not predictive of anything and is based on logical fallacy. It is impossible to falsify.
There is not a thread of evidence to suggest that. You do realize that bearing false witness is breaking the 9th Commandment, don't you?