I'll do my best. I've done law for a year and here are some of my observation. Feel free to correct me if I'm wrong anyone.
1. Will the fact that i havn't done legal studies hurt me in anyway in the law degree? absolutely not. however I do recommend doing some sniffing and finding what textbooks you're going to be using, and at least start having a flip through them in the holidays in order to get a leg up on the rest of the students. law texts are very weighty so don't get too flustered by the amount of 'stuff' in there... half of it you probably won't need to know. your course lecturers and tutors will narrow down the most important parts.
2. Is Macquarie a good university for law? yes it's fine. I go to UTS and apparently Mac ranks up there with my Uni. Sure they don't have the prestige factor of a USYD or UNSW but I honestly believe that the quality of teaching is just as good. sure the candidature might not be the absolute cream of the crop, because the cream usually goes to the more prestigious uni's, however, in the end, if you have good marks employers will recognise this. bare in mind though, that if the brightest are attracted to the very 'top tier' uni's then you might have to produce a higher mark or rank higher within your cohort to really distinguish yourself.
3. Do employers consider usyd or unsw graduates over mac grads? see above. you could be a mediocre student from usyd or unsw, but a great student from mac or UTS would get preference (just thinking logically).
4. How difficult is it? having done 1 year... I'd have to say that it isn't difficult to pass. It seems fairly difficult though to get a distinction average, you really need to sink some time and effort into getting great results. remember that most people in the course are in the top 1 or 2 per cent of the State as determined by the HSC so competition will be much tougher than High School. for me this seems to be reflected in the amount of time and effort it takes to get very good marks.
5. If you are in the degree are you enjoying it? I'm doing straight law, and I wouldn't say I'm 'enjoying it'. but then again I've tried a lot of things and haven't really enjoyed many of them. for me this is just a means to an end ($). Practising law will be more interesting hopefuilly
Then again, it is a challenging intellectual exercise and you do feel a big sense of achievement when you finish a subject, or a difficult assessment.
hope that helps in some way.