For question 15 and 16 under additional information it asks us to list ECs and rewards received. Does this mean we simply list the activities or should I enter a description of each EC?
Depending on how many activities/ECs you have, you may either describe or list them. One way to incorporate both styles and save space is the following:
Research Assistant in neuroscience/Harvard University/2000-2001/Conducted experiments in cochlear biophysics.
I simply listed all the awards and EC's. I believe you will find that insufficient room is provided to list everything you desire even without descriptions.