Having done bronze silver and gold duke of ed I can say I definitely found it worthwhile, even doing gold throughout year 12. Gold and silver are both highly regarded for applications but that being said I agree with carrotsss that you shouldnt d it just for the applications. Also, the camping...
I think on average single sex girls schools do outperform single sex boys schools but there seems to be a weird pattern where the boys schools are more polarised in the results (higher concentrations of both the best and the worst results). not sure why this is
english cant really ever have good scaling because its cohort is just the entire hsc cohort and therefore it's basically impossible to have high scaling unless one particular english has exclusively good students and the other will then have even worse scaling