1) OK
2) We undestand that the witches have the power of knowing something about the future, for they are able to tell us that the battle with be over before sunset.
3) Unlike most of the other characters, they speak in rhymed octosyllabic, a very popular verse form of the late Middle Ages.
4) Macbeth has almost forgotten the taste of fear. There was a time when his senses would have cooled to hear a night-shriek, and the hair on his neck would have risen.
See the synonyms for "hair-raising" here: http://www.answers.com/topic/hair-raising
5) He has had dinner with horrors. He therefore acknowledges that his past actions were terrible and murderous, Now horror cannot startle him any more.
6) When his lieutant asks him if he hears the cry of a woman, he simply asks what the noise is. He has no particular reaction, though in the past he would have been alarmed or scared.