You should always print your exam papers to mimic the real exam. As for answers, you can cross check it with a textbook or get your teacher to mark it.
HSC externals are where it really counts but you need to be well ranked as well. If not you better hope that you and your cohort start working like crazy from here on in.
Wouldn't say it's just luck. Most likely that they have gone through the rubric, identified all the 'main' possible questions which may come up (there's probably around 4-5 solid big idea sort of questions they can ask here). Then they just practice their generic essay numerous times answering...
You don't have to remember every single little piece of information. Make sure to have the 'big idea' concepts down and then start working on past papers ASAP!
True, but you need more than just the quotes. HSC English (unfortunately) forces you to memorise a lot and you just have to play the game I guess. From experience people atleast 8 out of 10 people who received band 6s in my school memorised significant amounts of their paragraphs and analysis.