The evidence for their being better at this than laymen is at best mixed. Editors and media are bad at sufficiently filtering things like climate change denial and creationism, while faculty and administrators are better. I would argue that everyone on that list is likely to have a "neutrality bias", by which I mean they are often more concerned with appearing "objective" or "centrist" than they are with saying true things. Both the left and right operate large "flak industries" to try to shift what counts as "objective" in one direction or the other.
They became better with racism, but only with the help of popular movements. Legislation made them better about persons with disabilities. We're seeing similar shifts right now concerning sexism and homophobia.
It would be difficult to get an very accurate picture of where such elites do well and badly. The metric would have to involve a specification of what counts as "correct" or "popular" morality, as well as the epistemic merit of a huge variety of politically-charged positions. If you want to get past simple outcome-based statements concerning a specific position, it's a hard problem. Do they do well enough to maintain a diverse, intellectually stimulating environment?
Media editors? No. Corporate boards and managers? Sometimes, but very often no. Publishers? A mix. University administrators and faculty? Mostly yes.
Are they "getting it right" when they select against racialists and Stalinists? Yes.
What standard are you using to judge whether they're correct or not? I disagree with most of your answers. I'm guessing that if I pressed you enough, you'd wind up answering "the gate keepers (especially the ones at universities) are more-or-less doing a good job, I know this because they told me so".
Related: Heuristics for Evaluating the Soundness of the Academic Mainstream, Admitting to Bias, The Ideological Turing Test