Well, I don't think is is more study than learning maths. Different type of work, though. I would say that there is lots of memorisation involved, but that is it nowhere near as intellectually demanding as maths. Basically if you put the time in, you get the results.
Can you read Chinese fluently?
If so, you probably have some sort of an advantage for the reading/vocab part of the test. When I did the JLPT, it only tested passive language skills - mostly reading and listening. I was living in Japan at the time, so I found the listening section really easy. But if you are in Australia, with less exposure to spoken Japanese, it could be harder for you. The reading and vocab is not too bad if you have done a lot of reading. The part that I found the most difficult was the grammar section of the exam.
Dunno if they have changed the format of the test since then.
You know that you can do a diploma of arts in Japanese at UNSW?
http://www.handbook.unsw.edu.au/undergraduate/programs/2009/3417.html
