My view on the free market is informed by Ludwig von Mises and Murray Rothbard, amongst other scholars of the Mises Institute and more loosely of the Austrian school of economics, so I guess you can direct your critique of the definition of free market economics to them. I'm primarily working on the heuristic of praxeology in conjunction with my formal education in psychology, so hopefully that puts my thoughts into some context.
The purpose of ethics is to determine how a body politic will normatively govern the use of force, whether that normative standard is teleologically based or deontologically based is the main paradigm up for debate. You correctly identify that discrimination as an action is not force, yet it is not self evident that such an action is not ethical in any way, thus you have to make an argument as to why you believe it should be teleologically unethical. I think the deontological argument for deeming discrimination unethical is unsustainable because the very argument is predicated on discrimination in order to stop it, in effect one must discriminate against discrimination because discrimination is unethical, thus one must not discriminate against discrimination because discrimination is unethical. This is an internal logical contradiction.
Ontologically speaking, discrimination can not be unethical because it is a requisite action necessary to exercise individual property rights, specifically free association. Modernist society normatively emphasizes advocacy for enfranchisement of the minority, with most modernist societies then arguing that the individual is the smallest minority. Deeming discrimination unethical would complicate other areas of ethics because it interferes with free association, then runs afoul of the non aggression principle that is one of the premises of capitalism.
No, force exists as a fact of nature, ethical systems only normatively govern how moral agents will utilize it.