Firstly congrats on your acceptance.
1. & 2. The people most likely to fail are those who aren't prepared to put in the effort required to pass the course because they think they know it all or because they are too lazy to try and do it the way the ADF wants them to. Previous flying experience can be both a help and a hindrence. Don't concern yourself with it. Concern yourself with listening to your instructors and doing as they tell you. I didn't have any experience to speak of when I went through and the people who were suspended first on my course were those who boasted a few hundred hours. With your study, if you can get a copy of the PAARM (the ADF coverall reference) that may help a little.
3. & 4. This concerned me a little mate. If you are only 6 days from the FSP an you haven't got a firm grip on at least some of the roles you may be directed toward you should probably get onto the ADF websites and talk directly to ADF pers in the jobs. Some people on here have opinions based on theories and impression not fact so talk to a face if you can. I do not mean to say that there is not a wealth of knowledge and experience here but when you don't know any better it may be hard to decipher the current situation from other less accurate points of view. Go visit a base if available. I won't espouse opinions on roles, I'll leave that to others.
The rest. Don't worry too much about 'catching up', it is a screening process not the actual course. Prepare yourself by figuring out why you want to be a military pilot because ultimately that is what will be the motivation you are going to need to pass the actual (a quite a full on) course.
Good luck with it, it will be as rewarding as you make it.
TW