*disclaimer* - I really don't know. This is just my 2c maybe with the htread bumped, someone who does know will reply

The deliberate use of metaphors, emotive language, rhetorical questions and punctuation work together to illustrate the depths to which the teacher has sunk, and to highlight the hopelessness which he feels. <- should the words in red be as they are, or should they be all plural or all singular?
The words in red seem ok as they are to me. I don't think it sounds right if you change them all to a singular - change metaphor and it just doesn't sound right. Ditto punctuation - no such thing as punctuations? so needs to stay as it is.

I think you could take out 'which' and just have 'hopelessness he feels' ?



Metaphors are the most significant literary technique used by Lawrence. <- should metaphors be singular? Or should 'technique' become plural?
Again, I think as it is sounds right? How else could you put it... Metaphor is the most significant..nope.... and changing techniques to a plural doesn't work either.


Dark words such as ‘waste’ ‘abyss’ and ‘consume’ can be associated with depression, which support the teacher’s view that there is no purpose to either his teaching, or his students’ learning, and how he feels about teaching itself. <- Should that comma in red be there, or is the sentence just too long either way?
I think it is a bit long... and I think it's too many commas. Can you replace the last comma with a semi colon; and change 'and' to 'nor' or 'neither' or even repeat 'no purpose' or something.
So, 'Dark words such as ‘waste’ ‘abyss’ and ‘consume’ can be associated with depression, which support the teacher’s view that there is no purpose to either his teaching, or his students’ learning; nor any purpose to how he feels about teaching itself.


An example of this would be having the students physically portrayed as the ‘unruly hounds’ which the teacher describes them as in the original text instead of children, and have them sitting at their desks, straining against their leashes and scratching at the floor with their feet, while their leashes are held by the teacher as he sits as his desk. <- clearly this sentence is too long. Would it be acceptable to have bracket around this sentence 'which the teacher describes them as in the original text instead of children' or not? or just leave it out altogether?
You could take it out, but if you leave it in I would definitely put brackets around it. I don't think it needs to be in there though, you know?