
Ryan S. answered 03/26/19
PhD in Philosophy with more than 6 years of experience teaching logic
Let's first look at the relativism question. If we assume first that morality is merely relative to particular cultures and thus that what is "right" in America is just what is right-according-to-our-moral code, it still doesn't follow that wearing braces is "right" in this sense because the mere fact that something is a cultural practice does not mean that this practice is considered morally right according to our culture's moral code. I don't think that getting braces is treated as a moral requirement in our culture; it is rather something that is morally permissible to do AND morally permissible not to do. But if our moral code says that it's okay to not get braces, then it's not "right" to do it in the sense that it's morally required of those with defective teeth.
As for the second question, yes, utilitarianism would say that taxation is indeed a morally good thing provided that it maximizes overall happiness in the world. In fact, utilitarianism would say that taxation is morally required if it maximizes overall happiness in the world.