Why do so many people ask this question? Don't you people read the UAC handbook/website, etc...? Your gonna get a BIG shock when you start uni and are not spoon fed anymore. No one to tell you what forms to fill out, units to do etc. - you have to read all this for yourself, and no one is there to tell you if you havent done something or done something wrong, until you come to the end of your degree and cant graduate.
93.40 was the 2006 UAI cut-off. The 2007 UAI cut-offs are not released until after the offers are made.
NO. You are NOT definetely in. If the UAI cut-off increases, you wont get in in the main round offer. For B Commerce at the University of Sydney, the only criteria is a UAI greater than or equal to the UAI cut-off. (Don't forget the late-round offers if you are unsuccessful in the main-round).
Yes, you can change after a year into B Com/B Laws. It is a very competitive process and if your UAI is indicative of your academic ability, unfortunately the prospect of you transferring is low, when others who have UAI's of 97, 98 are trying to transfer as well and get D's and HD's. Transfers are based on grades; those with higher grades get in first and so on until all spaces are filled.
Hope this helps.