This is the flip side of the arguments I think you're alluding to, that the faulty thinking was actually beneficial in the EEA.

Yes. Some people I know, observe fact X about human behaviour and then conclude that it had to be beneficial for survival, for otherwise evolution would have eradicated X.

I do think we're getting sidetracked by your halo effect example, though -- it might be useful to give three or four examples to avoid this (although if each one has a different explanation, that might substantially increase the effort of presenting your idea).

My original plan was to give several examples of biases with different explanations, but since this is my first attempt to do something productive on LW, I decided to write a short article and get some feedback first. So, thanks for your suggestions!