Shakespeare has used the noun, “crown” deliberately to subtly indicate her desire to become queen as it seems like she is already imagining herself with the crown.
Also, the superlative “direst” portrays Lady Macbeth as completely evil as she wishes to be filled with “cruelty”.
Also, not a major mistake, but don't use contractions such as 'doesn't' in your first paragraph, keep a formal tone. E.g the snake could be a religious allusion (reference to Adam/Eve story - power of evil) and link that back to your point. A few points could be evidenced and considered further, however.
Also, when you talk about the 'sin', mention that the audience would have been extremely religious at the time so it is a very effective technique to use. With your first point regarding Macbeth’s ambition at the start of the play, there are some other quotes that could be used: ‘Stay, you imperfect speakers’ ‘Speak, I charge you’ ‘Rapt withal’ His soliloquy in Act 2 Scene 1.
Later in the play, Macbeth’s ambition is clearly presented as his fatal flaw which ultimately leads to his downfall from the “worthy gentleman” to “hell-hound”.
In Act 3 Scene 2, Macbeth is now king after murdering Duncan and is fearing for his position for power, “We have scorch’d the snake, not kill’d it.” Macbeth still fears that he could lose his power, highlighted by Shakespeare’s use of the metaphor “snake” which connotes threat and danger, especially because of the witches’ prophecy to Banquo that his descendants will become kings.
You have also identified a range of literary devices and have talked about the contemporary audience (context). To improve, you could start with a more clear point (thesis statement). Throughout the play, Shakespeare portrays Macbeth as ambitious to a certain extent ...
(mention that he is ambitious but his ambition is hindered by fear).
Shakespeare’s use of the noun “babes” emphasise Macbeth’s malevolence as it connotes innocence and purity which completely juxtaposes Macbeth’s violence.
This would be seen as completely unimaginable to the 16th century audience who believed that men should follow the Chivalric Code of Honour which states that a man should not even fight a foe who is weaker than him but Macbeth ruthlessly murders a defenceless family, “spurred” but his ambition.