I haven't flown in Australia for over 10 years, I do hold an Australian ATPL and an EASA one.
In Australia, you have to do the CPL exams as well as the ATPL exams.
When I did them, you needed to pass all of them at the one sitting (over 2 days) to be given a pass but I believe that has now changed.
The EASA ATPL material versus the CASA ATPL exams? I'd say the same amount of "stuff" but whereas the EASA ATPL theory is a lot spread "thinly" the Australian ATPL theory is the same amount of stuff to learn, just less broad but a lot more in-depth.