From a quick look on Wikipedia it looks good. Regarding picking that or private talk it through with your parents and ask others I really can't decide for you
Remember year 7 is only one year of your high school study and shouldn't be of much concern since it doesn't affect your atar, for me it...
Really depends on the school but I would think they aren't as competitive as selective. Imo private can be a waste of money if the teachers are bad so take that into account, again depends on the school.