Hello there. I'm from IJC... and a girl 
Actually, the school starts at 8am and end usually at 4.40pm except
on long days where it ends at 5.10pm. Wed and Fri are short days,
end at around 2+pm
And no, the teachers aren't that strict from what I know, they
sometimes also slack slack wan.
My first 3 months there, no need to wear full Sec school uni, just
the skirt and a shirt that is issued by Innova. It was the same
even for the batch that came after the first 3 months.
Ok... now about the uniform colour, it looks a bit similar to tjc's
although tjc's is darker green in colour, but still I like to be
mistaken for a tjc girl haha. 
There is actually a back gate that is open in the morning as well
as after school so you don't need to walk very far. Around 5 mins
from bus stop to school.
Wow, very point form leh 
EDIT: Opps, I had to edit to emphasize that the skirt you wear
during the first 3 months is your own sec school skirt, not the
Innova one.