STRONG ENOUGH (CHER)
Tentative answers
Ad 1) The singer ("I") adresses her partner ("you"), i.e. "you" does not mean the whole audience.
Ad 2) A woman discovers that her boyfriend/husband has been unfaithful, has slept with another woman. As a consequence, she wants a separation. She feels strong enough to live alone.
Ad 3) Yes, because a sexual adventure is not so serious. He does not get a chance to defend himself or apologize ("there’s nothing you can say", "there’s no more to say". No, because this cannot have been the first time he has betrayed her ("you’ll never change", "on being used I could write a book" "I quit crying long enough"). Maybe she has kicked him out before and has returned ("this is our last goodbye").
Ad 5) Girls/women, you are strong. Don’t let men use you, don’t just tolerate everything that is done to you ! This is radical in so far as it is the traditional female role to be tolerant and weak. Cher represents a self-confident, emancipated woman, who encourages other women to take their fate into their own hands.
Ad 6)
a) self-confident: she does not let him talk himself out of it.
b) emotionally strong: she does not give in, because she is not afraid of being alone.
c) being able to support herself: she is able to earn enough to make a living
Ad 7.1.) Song "Take that look off your face"
Ad 7.2.) This song is based on the opposite attitude: She could not live without him.
Ad 8) The Cher-biography by J.Randy Taraborrelli (1989) tells you that she had more than one unhappy relationship with men.