Both monkeys and apes (and humans) are said to be simians, so I don't see how it gets the lineage wrong.

Because monkeys are a separate branch of the family tree, a branch which does not include Homo sapiens. Therefore it is simply incorrect to involve "monkeys" anywhere in the discussion, period. Humans are not descended from monkeys in any way. Literally nobody believes this.

What is the crucial nuance that makes statement B true and statement A a strawman? Admittedly, statement A is exaggerated and simplified, deliberately pointed, but I don't see how it's outright false. It gets the ballpark right.

I already explained exactly what the problem was. I won't do so again.

And no, it doesn't "get the ballpark right" any more than the "what caused God" argument gets the ballpark right on first cause arguments. It doesn't "simplify", it displays a stunning, and I mean stunning, degree of ignorance of what is even being proposed. In fact, if I remember correctly, Dr. Feser explicitly uses the "monkeys gave birth to humans" as an analogy for precisely that. Of course, tautologically the statement "apes give birth to humans" is correct insofar as it happens all the time (humans, in strictly biological terms, are a type of ape, and thus give birth to apes).

No inherent problem, especially considering God, in principle, as the source of all causality in the natural world.

One possible issue might be with ironing out dogmatic (?) declarations by various Popes vis à vis methods for interpreting scripture. Were I to be dogmatically beholden somehow, to accept six-day creation 6 000 years ago, then things might get "interesting" (although at that point its more about geology and astronomy and the theological problem of the intelligibility/deceptiveness of the created universe than about biological evolution).

Other than this, what concerns me is that I see so many people with whom I am otherwise sympathetic (Catholics of a more or less traditionalist bent) making transparent errors in dealing with the concept of evolution. For example, ubiquitously agreeing with the non-scientific metaphysical claims popularly packaged along with evolution, and jettisoning the baby with the bathwater. This is often coupled with equivocation (associating biological evolution one-for-one with doctrinal evolution) or frustrating straw-men on the level of "monkeys giving birth to men" or what have you. To say that this doesn't damage their credibility, and thus my confidence in my own beliefs, would be a lie. If they're so misguided here, what else are they wrong about? It really does bother me.

After reading up quite a bit on the Thomistic view on angels (fallen or other), there is one thing which I don't quite understand, namely, how exactly they interact with a human.

According to Dr. Feser's post ("Cartesian Angelism") and numerous other sources on Thomas' philosophy, angels (and thus fallen angels) are forms without matter, I.E. pure intellects which do not have senses and do not employ reason and observation to arrive at knowledge. It is also Thomas' view, expressed elsewhere (of demons), that they also are unable to "read your thoughts", so to speak. I am already rather acquainted with Thomistic ideas, having read both Thomas' works and secondary sources such as Feser's books. The arguments supporting both assertions seem to make sense.

However, there is a problem. Or seems to be.

If demons do not have senses, and are thus unable to observe your actions, but are also unable to "read" your thoughts, how can they know anything at all about you? How also would it be possible for a demon to tempt you, unless its immaterial form were able to somehow interact with yours (such as implanting thoughts, perhaps)? How would any of this work within a Thomistic framework?

This seems to pose a sort of "interaction problem" of its own, similar, but not identical, to the one posed by Cartesian mind-body dualism.