In the HSC as sad as it is, quantity is somewhat prioritised over quality. If you write 2 pages and the girl next to you writes 6 (we all know those people!) then they're more likely to have more analysis and quotes to back up what they are saying. If you're just slow to write, I think practising is the only option really.
Aos: discoveries can affirm your perception, discoveries challenge your perception - very common and most of the questions can be moulded around this. If you're going to memorise one essay for any of them, probably recommend discovery
Module a: just memorise generic things about how the change in values is present in the texts. How does the textual form adapt to the times, how are values portrayed, how are some aspects of the original text highlighted and why are others hidden. You can ease it into your argument
B: too risky imo. If you do poems or speeches, don't try to write an essay for each one! You might be asked on just the introduction or a particular scene or even techniques like imagery! just have as many quotes as possible
C: i think knowing how representation works and having a few phrases about it that really solidifies your argument will also be good