Film Reaction: The silly King

I absolutely loved Goold’s Macbeth. One character that I though was portrayed particularly well was Duncan. I found it interesting and fitting that Duncan seemed to be an idiot. I don’t mean that he was stupid, but that he was rather silly, and foolish. He was beloved by his subjects and his sons, and, and MacDuff says, was a good King of Scotland. He is portrayed as a good man, though not the sharpest knife in the drawer.

In the film Duncan is the least imposing man among the group in the opening scenes.  While the others seem a little intimidating, Duncan seems more jovial. His language both in the play and movie is more flowery and happy than thoughtful. This language is used to advantage in displaying his mild character as he speaks to the Captain who is reporting the battle. While the Captain is struggling through his injuries to describe the battle, Duncan commends his with great ardor. In the film his praise seemed rather out of place and out of touch with the gravity of the moment. Malcolm's firm grasp of the Captain and the other men’s’ solemn, approving nods seem to fit the situation better.

I believe this is how Shakespeare wrote Duncan to be. Duncan seems to be easily duped, and Macbeth is not the first one. Cawdor before him was one of Duncan’s closest advisers, and betrays him. Duncan himself gives a speech about how hard it is to read a man’s true character behind all his smiles. Yet he makes the same mistake again with Macbeth. Duncan’s foolish trust is highlighted by his sons’ greater wisdom. They choose not to trust Macbeth’s false grief up on Duncan’s death.

The film’s portrayal of Duncan as jovial, kind and simple if very fitting, and, I believe, in accordance with Shakespeare’s intention.
Questions:
Why is lady Macbeth washing the kitchen wall when Macbeth comes in?
why do the witches dress the blood sack the way they do before meeting macbeth? what is the significance of the glasses and coat?