Is Macbeth a moral play? Is justice served at the end of the play and how can you defend whether or not it is?What makes the play this way?

Morality is often in the mind of the individual, but some areas of morality are commonly accepted, particularly that it is wrong to murder someone.  Macbeth commits the murder of King Duncan.  His reason for murdering the king is to expedite his own ascension to the throne.  He commits the murder for his own gain.  This makes the killing immoral (versus his previous killing of Macdonwald which was acceptable because Macdonwald was a traitor to Scotland).  Macbeth himself said he had no good reason to kill Duncan , "...but only vaulting ambition..." (Act 1, sc. 7).  Macbeth allows his wife to talk him into killing the king, but he had already considered the idea of killing Duncan in Act 1, sc. 4 when Duncan announces that his son, Malcolm, is the crown prince.  Macbeth says, "Stars hide your fires! Let not light see my black and deep desires."  He thinks of murder before he speaks with his wife, so she only fanned a flame he lit himself.  Justice is served, if you view justice as "an eye for an eye", i.e., Macbeth is killed by Macduff in the final act and Macbeth had not only killed Duncan, he'd had Macduff's family killed as a means of punishing Macduff.  Macbeth's killing of the king served his own ambition to get ahead, but his killing of Macduff's family served no purpose.  He was angry with and feared Macduff, not his family, so the senseless slaughter of Macduff's wife and children was the act of a merciless tyrant.  But again, the question comes down to your own morality.  Is it right to take a life as punishment for taking a life?