Is Macbeth a moral play and if so, then is justice served?
At the risk of putting the question back on you, it depends on how you define moral.
Certainly many many immoral things are done in the play. People get killed in cold blood, and they are relatively innocent people.
However, if you focus on Macbeth's ultimate fate, then I'd say yes, it is a moral play. He is overthrown, and he and Lady Macbeth die or are killed. Before they die, they suffer. That is a harsh kind of public justice.