We couldn't be bothered. Team interwebs had just gone through the judging, and us showing our access cards straight after that would have been lame. :p
Most of the textbooks for science are recommended. They won't force you to get one unless there are assignments based on the questions in the book (eg. Physics).
When you buy course readers, you can either use a credit card or your extro account. You need to first put your own money into it by visiting a computer lab at usyd.
I'm not sure. The summer school bit means it's sepcifically for those subjects run during summer school, but I'm not sure if this would be any different to the course in semester 1.
When your UAI is calculated, they only take into account 10 units worth. Many people have 12 units because 1) 2 units don't count towards a UAI or 2) They would like to have a back-up subject in case they don't do well in a particular subject.
I have the opportunity to have 8 hours straight on Tuesdays without any breaks so I could get most of Wednesdays off. I actually considered it until I noticed that there was a biochemistry lab from 10-1, and then a chemistry lab staright after that till 5. *shudders*