There are two extended responses in the HSC, one is in the form of a business report which requires no case studies (just reference to the stimulus material) and the other one is an essay where you have to use various case studies. (correct me if I'm wrong).
Physics is quite objective... so uh, as long as you understand everything that you copied from your friend it'll surely save you time than having to get the info from scratch.
I use the preset blue headings (heading 1, heading 2) it's so much better for organisation and you can do sub-sub headings etc. If you use word you can also ctrl+f and it is easier to go through your dot points.
I prefer to use One-Note for my notes, though.
Drop whatever you are performing worse at, and also if you want to do something like Engineering at Uni you should keep Engineering studies, it's probably not compulsory but it'll help I guess.
Are you doing 14 units? :O
I'm probably dropping Ancient History as it'll be no use to me in the future haha, I'll finally have free periods :)
I'm probably going to take on Extension English though, so I'll have either 11-12 units. How about you?