Could someone pretty please answer this? it got ignored amongst other discussion 
I also did 8 science with no breadth in first year.
Yes, you can only put 5 subjects in your "BS-SCISUBLV1 - Science Level 1" section - you will have to put the other 3 elsewhere on your study plan, e.g. "BS-SCISUBLV123 - Science Level 1, 2 & 3" or "BS-SCI&BREADTH - Science and Breadth". You don't need permission from the Student Centre like John President said.
This might be problematic if you don't want to waste three slots in your study plan on first year subjects. However, since I was enrolled in a Diploma in Mathematical Sciences as well, I enrolled in 2 maths subjects outside the BSc, so I only had to enrol in 6 science subjects. (I put the extra one in "BS-SCISUBLV123 - Science Level 1, 2 & 3".
Hope this helps!