Did not read everything yet, but on the first example I really disagree.

Maybe its because I am not a native speaker, but when I read the question "Discard draft" and I see the options Yes and No, that is clearer to me than Cancel and Discard.

Because when I see this message I am in the process of cancelling something. But Cancel in this case would cancel the discard process… Perfect would be "Discard draft" with the options Yes, Discard and No, continue. In this way you communicate the action on the buttons.

Another solution would be to rephrase the question. The concept of cancelling the discard is hard for me to process. If the question was What do you want? with the answers cancel and Discard Draft, it would make more sense.