Well a predicted ATAR is exactly what it is, predicted, anything can change so it could be either very accurate or not even close depending on the situation.
The motivation thing is pretty common I think, mainly after assessment tasks ie trials you just can't be bothered working anymore. What worked for me was thinking about not getting into my preferred uni degree, but everyone is different. You should have an inner motivation for doing well. So...
Nah i know one of the people who wrote the 4U paper this year (Family friend). She is just a normal teacher. I think they source them from various types of schools. ie catholic, private, comprehensive etc
Overall feeling confident, essay questions were exactly as I had predicted, some dodgy multis, SA pretty straight forward, no curve ball questions really.
Probably not, you haven't really analysed it properly. But who knows what the marking criteria is, so just hope for the best i guess. No point fretting over this when you have other exams as well.