Excellent points we need to consider.
No title of nobility shall be granted by the United States: and no person holding any office of profit or trust under them, shall, without the consent of the Congress, accept of any present, emolument, office, or title, of any kind whatever, from any king, prince, or foreign state.
It just struck me that I read that the Nobel "peace prize" committee is actually a creature of the Norwegian Parliament. If so, accepting the "prize" is illegal without a vote of Congress.