The 2 halves of "Billy Budd, Sailor"

What can I possibly say that hasn't been said of "Billy Budd, Sailor"? 
The story is cut into 2 halves, by the scene of John Claggart speaking to captain Edward Fairfax Vere: 
- The 1st part is chiefly about 2 things: Claggart's envy and Billy Budd's innocence. 
Regarding envy, Melville makes an interesting point: 

"... Now envy and antipathy, passions irreconcilable in reason, nevertheless in fact may spring conjoined like Chang and Eng in one birth. Is Envy then such a monster? Well, though many an arraigned mortal has in hopes of mitigated penalty pleaded guilty to horrible actions, did ever anybody seriously confess to envy? Something there is in it universally felt to be more shameful than even felonious crime."

It makes me think of a passage by Angus Wilson: 

"All the seven deadly sins are self-destroying, morbid appetites, but in their early stages at least, lust and gluttony, avarice and sloth know some gratification, while anger and pride have power, even though that power eventually destroys itself. Envy is impotent, numbed with fear, never ceasing in its appetite, and it knows no gratification, but endless self-torment. It has the ugliness of a trapped rat, which gnaws its own foot in an effort to escape." 

Linked to the theme of envy is the theme of evil and human nature. Knowledge of the world and knowledge of human nature are "distinct branches", and some people, like Claggart, are "a nut not be cracked by the tap of a lady's fan". This theme is connected with another one- Billy Budd's innocence, or his inability to recognise and acknowledge evil. 
- In the 2nd part, Billy Budd fades into the background. He's still there, the characters talk about him, the actions concern and affect him, but the 2nd part is more about captain Vere- more specifically, his rigidity, his reasoning and all of his actions that cause Billy's death. 
There can be several themes: Vere's rigidity and his abstract thinking (reminiscent of Shakespeare's Brutus), the law (Vere mounts a drumhead court instead of turning the case to admirals, and takes over as sole witness, prosecutor, judge, and executioner), and the harm of the inaction of those who are unable to change a thing (intellectually inferior, the men of the drumhead court are unable to articulate their disagreements or hesitations) or who are able but indifferent (the surgeon and the chaplain), for example. 
"Billy Budd, Sailor" is so rich, as Melville's works usually are. We can go on and on and talk about other themes, like Christ, Adam, angels, father and son, Abraham and Isaac (if Vere is Abraham sacrificing his son Isaac, that is, Billy Budd, what does he sacrifice him for?), conscience, fate, God, Billy's last words and Vere's last words, the falsified report... but I'll stop here. (If you're a student stealing my ideas for an essay, please let me know which grade you get). 
What I find really interesting is how sharply divided in half the story is, at least that's how it feels to me.
Do you feel the same?