Headscratchers / Macbeth

• Instead of letting them die at the hands of Macbeth, why didn't Macduff just take his family with him to England?
  • There was no reason to; Macduff had no indication they'd be slaughtered.
  • To be completely honest, it probably didn't even occur to him to take them. Lady Macduff's language when she's talking to the Thane of Ross about it indicates that Macduff literally just ran away without telling her or his children anything, and when Macduff is told of their deaths, he has a couple of lines that indicate he feels as though he was selfish to leave them behind. It's likely he figured that Macbeth would be coming for him at some point, so he just cut his losses and ran and he probably thought with him gone, Macbeth wouldn't bother going after his family. In other words, he ended up grabbing the Idiot Ball for a while.
• Who sent the messenger that warned Lady Macduff (too late, as it turned out) the murderers were coming? The dialogue indicates he was a stranger to her and therefore not a servant or lookout stationed at the castle. For that matter, how did he get into the castle in the first place? He just shows up with no explanation.
  • Probably one of Macbeth's people having an attack of conscience.