"Equal opportunity" is an unattainable goal, like "utopia". It sounds good in the abstract, but "equal opportunity" is such a subjective concept that it's useless for any practical purpose. Every person's life is as much a product of random chance as innate potential, so there's no objective measure of equal opportunity by which a society that enforces equal opportunity could be judged. (Very much /s, of course.)
The point being that any arguments made against the unattainability of true meritocracy apply just as well to true equal opportunity.
By the way, targets do not need to be attainable in order to produce (also quantifiable) positive effects.
And measuring skills is not?
In short, a "skillocracy" tends to look and act very, very much like an aristocracy, which is kind of the opposite of the idea I think most people try to express with the word "meritocracy".
When everyone has an equal opportunity.
You should be able to derive the rest of the answers to your questions from that.