Re: the longer hours.
I don't think I could stand the longer hours, and it's not because it would be more time at school. At my state school teachers allow us to spend time in their classrooms if we want (sometimes the teacher is there to help, sometimes not) to revise using certain books, or work in small groups. My school day officially ends at 3:30 so all the lower school students leave which leaves certain students who want to work for a bit longer at school the chance to in a quiet environment without the younger students being around. Two of my friends are almost dependent on this because they don't have a working environment at home. The extension of the school day would mean that we'd have to decide whether we can face staying at school until gone 6. In the lower years I would never have been able to cope, I used to go home relax for a bit do some homework and then spend some time with my family which is what I rely on now, the fact that when I didn't have exams I spent time with my family, with the longer day I wouldn't have even had that.
And, as for the later start I think this has a great potential as I've heard in certain schools that follow this design they allow their students to come in to school at the earlier time to go over their work and revise or have the option to sleep.
Question Time made some interesting points on Thursday...