As far as I know:
1. mainly Cantonese
2. about 30 min. (including waiting time)
3. spelling, simple calculation, questions about family life
4. Parents wait at the school hall while kids go to the classrooms upstairs.
5. I think there's only one round.
6. sorry, no ideas.
7. I don't think the school will consider it. But they like the kids with close relationship with parents.
8. The ones you've mentioned.
9. not neccessary.
10. Chinese.