ridiculing it and dismissing it making it seem like it is irrelevant
She’s down playing it because she doesn’t want to face the magnitude or the true extent of what they’ve done - regicide which is one of the ultimate sins in the Jacobean era
Downplaying it to Macbeth which downplays it in her mind so she doesn’t have to fave the gravity of the acts she’s committed
“You must leave this”
the direct address on “you” seems like a forceful attack on Macbeth, she has encouraged him to commit regicide and is extremely duplicitous because she made him do it to fulfil her own desires and her own ambitions
Now instructing him to “leave this” - the imperative shows she’s still got a power over Macbeth but perhaps she’s trying to have this power of Macbeth in act 3 because she is losing control and losing this power because thoughts are starting to engulf her mind
shown as she isn’t present in act 4 and she descends into madness in act 5
“Using those thoughts which should indeed have died with them they think on?”
the rhetorical question is that she is questioning Macbeth and questioning his guilt
Throughout the play, she continuously questioned him to threaten his identity as a man