Does sleep matter?

I mean, obviously. It's very important. Anyone who says otherwise is an idiot. :D

obviously you need sleep, but it would be interested whether or not 8 hours is required or if you could sleep for 3-4 hours at a time

No, not really- being a zombie is really cool, you don't have to nothing but exits

Yes, especially if you have school, I'd try and get atleast 6 hours of sleep, but you should be getting 8 or more. It can really fuck with schoolwork and grades, but its your choice.