Option 2 is correct: Macbeth killed the chamberlains during act II scene 3, where the sequence of events is as follows:
Macduff goes to visit Duncan in his chamber.
Macduff. I’ll make so bold to call.
For ’tis my limited service.
Macduff returns and reports that he found Duncan murdered.
Macduff. O horror, horror, horror!
There is no plot hole here. Macbeth killed the chamberlains in Act 2, scene 3, when the murder of King Duncan is discovered. Critics debate whether Lady Macbeth's fainting is feigned or real.
In Act 2, scene 2, Macbeth tells his wife after returning from Duncan's chamber about how the two chamberlains woke each other after one cried "murder&...
The phrase means "royal nature" and refers to two things. First, it refers to Banquo's character and is a form of praise. For example, a few lines further down, Macbeth explains,
to that dauntless temper of his mind,
He hath a wisdom that doth guide his valour
To act in safety
Second, it refers to the prophecy that the three weyard sisters (...
In “his royalty of nature”, “nature” means “innate character or disposition”, and “royalty” is used in the sense:
royalty, n. 4. Kinglike or majestic character or quality.
Oxford English Dictionary.
Then in the next line Macbeth gives us a metaphor in which Banquo’s character is compared to a kingdom, and the qualities that govern his character are ...