I did Classics in 2010 and Latin last year and never read the whole Aeneid... I really don't think it's necessary.
You probably won't start on the set Virgil until the second half of the year anyway, but reading the set book (I'm not sure which one it is this year, you can look it up on the VCAA site) in English and a summary of the rest will be enough. When it came to writing essays, I basically had a stock of examples from other parts of the Aeneid which I knew just enough about to mention and discuss briefly, which was good enough - you don't need to have actually read it all.
40+ raw is difficult but achievable, but it's worth bearing in mind that Latin is such a small subject that anything over 35 is a good achievement (and also basically equivalent for ATAR purposes).
Vocab is a really good idea. The unseen translation is 45% of the exam - you will have a dictionary, but the less you use it the better. By the end of the year, because I knew a fair (not amazing - a lot of people were better than me) amount of vocab and had got good with the grammar structures, I was really quick and that is seriously helpful. On the exam I did that 45% in about 20% of the time, and having extra time on other stuff is a huge help - particularly if there are some unusual things elsewhere on the paper, having time up your sleeve to figure out what to do with it is handy.
This is a really long-winded way of saying vocab and grammar. Do that.