he means he would be a messenger
because, the three witches told his future and said that Macbeth would be king. But then King Duncan said that his son would be king Malcolm. So lady Macbeth and Macbeth deicide to kill him so he would become king.
Not sure what you mean by that but historically malcolm army caught up with macbeth at a place called Lumphanan. There was a battle and it is said that macbeth was captured and had his head chopped off
who in Macbeth said 'the sleeping and the dead are but as pictures'
The witches had predicted that Banquo's descendants would become kings whereas Macbeth's would not. Macbeth resented that. Also, Banquo was aware of what the witches had said and might suspect Macbeth of Duncan's murder. Macbeth says, "My fears in Banquo stick deep."
Lady Macbeth
The witches never said "Macbeth, Macbeth, Macbeth". In Act 4, Scene 1, both the First Apparition and the Second Apparition begin their prophecies by calling out, "Macbeth! Macbeth! Macbeth!" Macbeth responds to the First Apparition by thanking it for warning him against the Thane of Fife (Macduff). Macbeth responds to the Second Apparition with: "Had I three ears, I'd hear thee."
Macbeth
Macbeth wrote a letter to his wife explaining to her all of what the witches had said. If he did not want her to be his "partner in greatness" he would have kept that knowledge to himself.
Macbeth
Macbeth did this to inform Lady M about what had happened so far.By this time,Macbeth was qualified for the throne,but it wasn't guaranteed for him to become king.
Macbeth. She said "Hail, Macbeth!" In fact all three witches say exactly the same thing.
The second apparitions said it to Macbeth.