While I understand this comment is made in jest, I do wonder whether cats are able to “map out” or recognize body parts of humans as parts equivalent on the cat body plan.

I have always wondered that about eyes in general: I'm not sure if I'm daft or not, but it seems surprising to me that animals with any intelligence look at us in the eyes.

Why fixate on the face and not, say, our hands or body, if they might be afraid of us, to determine if we are a threat? Eyes must provide a higher signal of intent, so it's surprising that even animals on a much lower level of intelligence can read our facial expressions.

I'm not sure if it's a good or a stupid question.

It's not a stupid question. It's a matter of stages of engagement.

The face and eyes indicate intention. You can't successfully track or kill without focusing your full attention on the object, and the easiest way to detect this is by seeing where the eyes are focused.

Once a threat is determined, then focus moves to other body parts.

My understanding is, in general, yes. At least major body parts and face parts. Even ones that differ (eg. our ears vs their ears).

Think about it this way how can you kill successfully if you don't have a basic understanding of the anatomy of what you're trying to kill?

I think a general body map is hardwired into more vertebrates. Heads always have eyes, ears and move around. Arms are on the upper torso and legs are at the end of the torso, tails are common.

Beyond that level, your guess is as good as mine though.

Anecdotal answer from a cat person: yes. My cat gives me "hugs". He stands on his hind legs on my lap so our hearts are touching and his cheek is against my cheek. It's quite touching. He seems to know what my heart is and what my cheek is, and puts his own versions against mine.

It's precious.