Is it not possible that society has an interest in broad employment, especially among people disadvantaged by such tests?

Very possible. I would take the Steve Sailer approach here, of acknowledging underlying differences and making the best of the situation. Let's step away from race and just talk about tracking in schools- by the time someone is 12, we have a pretty good guess what their eventual social strata / broad kind of career will be.

In countries like Germany, they respond to this with different high schools- someone who will be a technician can go to a technical school, and someone who will be an engineer can go to an academic school. Both get work suited for their intellectual ability and interests, and so the first isn't drowning and the second isn't bored. (Relevant here is the finding that getting rid of shop classes increases the high school dropout rate in America- turns out that for an easily identifiable group of students, the primary benefit they get out of high school is a place to practice basic handyman skills!)

In the US, we get lunacy like "whether or not someone takes the first optional math class is a very strong predictor of whether or not they go to college. Let's make that class mandatory for graduating high school!" which makes everyone involved worse off, as the students not pointed at college now find it more difficult to graduate high school.

For example: "It's been known for generations that physical strength has a positive impact statistically on outcomes in basically every sort of violent encounter, so as a default, in a world where couples and families could be attacked, people should assume a necessity for bigger, more muscular men as romantic partners."

I'm not sure this would see significant disagreement here on LW. The main response I would give is yes, but the preference is miscalibrated. Ceteris paribus, a stronger partner is likely to be better (assuming they aren't prone to domestic violence), but my reflective preferences would give a weight to athleticism that's orders of magnitude lower than the weight my attraction heuristics give athleticism. This mismatch seems to be because those heuristics were tuned in an era when the chance of being the victim (or beneficiary!) of violent crime was orders of magnitude higher than they currently are.