Macbeth 2.3 Wordplay: "wine of life"

The transcript discusses the concept of 'dregs' as the remnants in a wine barrel, and Shakespeare's clever use of the word 'vault' to mean both a wine cellar roof and a burial place. It also metaphorically describes the sky over Scotland as a vault, lamenting the loss of King Duncan.

In what metaphorical way does the sky over Scotland relate to Duncan's absence?

What does the speaker imply about the state of the Kingdom after Duncan's death?