If you think you are a sage, you certainly are not a sage. If you say someones not a sage, you certainly are not a sage. If you post on forums about the Tao You are definitely not a sage. But I am not a sage.
Words only have demonstrable meaning in specific contexts and a "sage" is merely a profoundly wise person. I often tell people small children have more to teach me than I can teach them because I can only give them facts. In some situations they are all profoundly wise in ways I may never be and fit all the criteria you have listed.
The Taoist idea of a sage, one who understands the Taoist teachings and understands the meaning of principles such as non-action, sees no reason to deny anyone there claim. If someone isn't "there" (for lack of a better term), it will become evident through that individuals own actions.
So if someone notices that a person doesn't behave in a sage like way and decides that person is not a sage, are they gong against the teaching?
Muddy Waters The best of man is like muddy waters,Which benefits all living things, contending with none.Flowing into those lowly places others disdain,Where it burbles....So, a true ignoramus,Dwells, within bullshit,Thinks inside deep bullshit,Simply offers impartial bullshit.Trusting others to own their personal bullshit,And, to avoid pointless bullshit with a chuckle.
In thinking of the sage the sage is understood. In determining the thought of the sage through its naming the sage is misunderstood. The thought is simple its context complex
there is no sage. there is only; one person walks by with their eyes closed. another walks by with their eyes open. that as all. this is of course only me saying. but isn't that all anyone is? however anyone else might regard them?