Macbeth - Act V and final thoughts

Act V is a retribution for all the terrible things done by Macbeth couple.

Lady Macbeth becomes mad, can't sleep and commits suicide. Macbeth is abandoned by all his lords and attacked in his castle by thousands of English soldiers. The witches' predictions came true, but not to the favour of Macbeth: the forest came to his castle, as soldiers held the branches in front of them to conceal their numbers, and he was killed by a man who was not born by a woman, but who was "from his mother’s womb untimely ripp’d". This is a nice touch that all the prophecies were actually correct, but not in the way Macbeth interpreted them.

Dunsinane Hill from Black Hill

So what the play is about? I think it is about fate and the will of a man. To which extent are our deeds predetermined? Can we avoid our fate if we stay faithful, honest and clean? Somehow all that was prophesied by the witches comes true, but it is also clearly shown that it was Macbeth's choice to begin murdering.

The play is about the natural order of things, which must not be broken, and that a murder is the most horrible of the deeds that can break this natural order. But it also shows us that this order will inevitably be restored, and life will go on. But not for those who have opposed the nature and have made their life as horrible as Macbeth's:

Life’s but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.