For example there is absolutely no such thing as an ancestral or paleolithical diet.

I'm not sure what you mean by this. Clearly you're not saying that our antcectors did not eat. Are you saying that humans have genetically adapted to different diets since the paleolithic? That still leaves the concept of ancestral diet as important. Are you saying any given human will be just as healthy on any diet? That's clearly false.

Human nature is tribal, we still manage to have nations and supranational organizations somehow.

By adapting the larger organizations to human nature, yes.

My "gut instinct" is on the middle way:

This suggests your suffering from the arugment to mederation fallacy.

we can change genders

Can we? It's possible for say men, to cut of their peneses and declare themselves women. (And in the west expect society to declare that they have always been women). However, in my experience the behvior of m-to-f trannies makes more sense if I model them as men who decided to "become women" as part of the especially male tendency to do crazy things.

I think it is meant not simply about differences, but when 1) differences are used to justify social customs that reduce the autonomy / choices of people, primarily women 2) differences of the kind that tend to assign lower status to women.

Does it matter of said customs are rational (say in the sense of leading to better outcomes)?

For example blog.jim.com says most modern women are "psychotic whores". This is not simply un-PC, it was a huge insult far before PC or feminism was invented, 1950 or whatever date you pick. It is not simply un-feminist or anti-feminist lingo, it is the lingo of louts who grew up in the gutter. It is simply incredibly un-classy.

Yes and in the 1950s a woman who behaved the way a typical women does today (at least in the west, I hear it's not quite as bad in eastern Europe) would be considered much worse then simply un-classy and loutish. And yes "psychotic whore" sounds about right for what they would of thought of that type of woman.

The second issue is that good luck about trying to separating facts from values in the fields that are not natural science but more like human, social concerns. For example, Marxists claim to have an entirely factual analysis of how the engine of capitalism works, but it is full with so much value-laden, mood-laden terms, that you cannot really separate the factual proposition from a general value/mood of them disliking hierarchical modes of production.

Yes it is. At least it is possible to isolate the factual analysis enough to see that it is false.

Also the context I am talking about is actually just one example of a more general category of negative contexts. Similar negative contexts are: The Gervais Principle, Machiavelli, Nietzsche, Social Darwinism, Objectivism. Generally ideas that cash out to saying life is all about brutal competition where winners take all and losers get screwed

Um, are you actually familiar with the philosophies you listed or are you going by the popular caricatures? Of the ones I'm familiar with, this is a rather bad characterization of Machiavelli and an absolute horrible characterization of Objectivism.