So when Trans4M says fifty pages, what he really means is something more like thirty pages on a bad day (including supplementary materials) and ten on a good day (usually no need to read supplementary materials). But then, in the textbook, one page is more or less A5 in size, so it really is only 15 pages of A4.
You also don't really need a passion for law. If you English Extension 1/2 and you understand how to critically analyse and deconstruct a text (usually a judgment), then you're well on your way to a distinction average. If you describe the case, then you won't pass.
Finally, law isn't that demanding. It's more of a group time activitiy where you discuss the material in the textbook (read the first paragraph) and clarify anything you misunderstood. You'll also get to watch numerous videos ranging from some dude who wanted his land back to some justices laughing at their own jokes. For USyd and UNSW, you only do one subject of law per semester in the first year so it isn't that bad.
Only JD courses are intensive. Check out their schedule and you'll see what I mean - especially if they elect to finish it in two years.
I disagree, 50 pages (A4) sounds more like the correct length and that's taking into account the same parameters that you considered. The weekly readings are well in excess of 75 pages and not surprisingly most often in the range of 100-150. The font is miniscule and on top of that, the writing is crammed. While the first year of law school is not overly demanding or difficult, it is by no means any indication of the work required in order to progress through a law degree. If you put it in perspective, the first year of university for any undergraduate student enrolled in any degree is not extremely demanding at all. Rather, the first year is structured in such a way that new undergraduate students are able to settle into university life.
Also, what one would define as a 'good' or 'adequate' mark is really only a matter of interpretation. However, given the competition in the legal industry and the oversupply of law graduates, exacerbated by a recent study which has shown that law students earn on average less than graduates of other disciplines, it is arguable whether a credit is sufficient, let alone a high credit. So this again will really depend on where you want to take your law degree. If you just want to pass, then it's really not that difficult so long as you keep up with your readings.
However, to simply suggest that Extension English equips you for a distinction average is misleading. The skills you learn in Extension English are no different to those in advanced or general English. While you are taught critical analysis in high school, it does not in any way prepare you for the level of thought, depth and analysis required at university. You'll find that the thought processes bear little similarity, if any at all, and analysing a judgment will feel extremely alien at first and somewhat frustrating. It's not a matter of simply being able to understand the judgment - understanding of which comes through critical analysis and not just merely reading it - but being able to apply it to any given process creatively and skillfully. Where a passion in law helps is where there are discrepancies between judgments and where no clear definitive principle exists. The higher level responses are then required to choose the 'best' alternative, which is itself a subjective and relative process, and must justify the choice made based upon personal convictions, developments in the law and rationale - Eg. notions of justice may come into play, or how a certain principle when applied in certain cases results in such injustice that it warrants a departure from the general rules or otherwise.
Asides from the obvious nature of tutorials in helping students to understand and clarify the material, it plays a much more important role. More often than not, the tutorials are led by members who were once or are currently members of the legal profession. Their insights help to bridge the gap between ideology and practicality. This gives students the opportunity to apply their knowledge outside of an academic sense. In the end, you are really in law school just to learn how to 'think like a lawyer', the law changes so rapidly that knowledge is fleeting.
Hope you make the right decision OP. But if you want to become an economist, which I am assuming from the choice of degree's that you have listed, it's best just to stick to a bachelor of economics degree and pursue honours. If RBA is where you want to work, that it is almost imperative for you to attain an honours degree in Economics. But then again, law does enhance your research skills and may work wonders for career prospects as an economist.