With regard to barrier free access, it seems like they didn't factor in that the distance from the street is a barrier in and of itself, particularly for the east pavilion due to its meandering walkway. Why there needs to be two full-fledged pavilion buildings is beyond me but, in general, these buildings should be much closer to Sheppard Avenue.
Maybe the west driveway could also be used as a bus loop for the 101 Parc Downsview Park bus, as it looks like it's not going to get cut back, and perhaps even the 108 Downsview bus. I don't know if the latter is heavily used though. The bus platform at Downsview Station is going to be a shadow of its former self regardless. It's not going anywhere. Having the 101 and 108 terminate at Sheppard West would save on fuel costs and still get passengers to where they are going. In the meantime, the 84 Sheppard West could stop in front of Sheppard West and continue onto Downsview, and beyond, ensuring the area still has bus service.