No. I don't think so - as long as you past finals it should be alright. If you continue with an accounting major make sure to grab as many freeby marks as possible. The finals are usually a whole new animal.
Re: If I do comm/law at unsw and do no extra curricular, will I be able to get a job
Having filtered through close to 70 or so resumes I can tell you that you are behind the eight ball. Close to all had work experience (not necessarily related to law, accounting or finance related) but they all...
UNSW hands down for IB. When it comes to campus recruitment, UBS/Citi/Goldman Sach/etc competitions and networking events the other unis don't even come close. Something you need to consider is that straight commerce might not be enough, you're competing against comm/law, actuarial and honour kids.