Jimny,
Do not worry mate, we are all confused by the numerous documents issued by CASA !
The best solution is to get hold of private study books...there are a few guys here producing them. They have practice exams as well.
Bob Tait being one. Google is your friend and will provide you with the answers.
Having flown here and in the UK, it is a lot less complex flying here (at the moment, pre EASA rules being introduced) than the UK.
AIP and ERSA are the ones you fly with...the others are written by lawyers to confuse you !
Also, there are a few guys acting as tutors, this is a good investment and they will sort out the BS from reality for you.
All the best,
Arrrj