I got an interview at Cinci for Sept 29th

and I have a couple questions about the extra questions that they throw your way when you go to confirm the application.
"Outline your work experience by year and semester, including number of hours. If you were involved in any pursuit that took up a large amount of time (examples include, but are not limited to, athletics, orchestra, student government, etc.), outline it by year and semester, including number of hours. Do not include work or other activities stated on your AMCAS application."
For this question, I don't have any additional things that I didn't put on my AMCAS.
I only filled out 11 or the 15 possible spots on the AMCAS. Should I just put N/A.
Also, for this question:
Discuss science grades lower than a B, semesters or years where your science GPA was lower than your average GPA, withdrawn (W) courses, and unusual course selections or changes in major.
Do they want me to go class by class> I don't know a way to answer this without making excuses.
I guess my overall question is why are they asking these questions and who is seeing the answers?