The job space figure includes institutional uses, so the actual office space is going to be much less than the 1.8 msf stated. I think it's deceptive, but it is clear what is meant if you read the panels.
Another issue is that art galleries usually prefer artificial or diffuse light, and it would be silly for any building on this site not to take advantage of its views. I think it needs to be taken into consideration when designing the building. For example, it could have an interior area with traditional display space and an exterior area, especially on the south side, with event space and large lobby.
On the Leidseplein example, traffic may technically be allowed there (I don't remember cars there) but mostly it's streetcars, bikes, and pedestrians. It's a beautiful square, a very good model for Robson square, being bisected by a narrow streetcar/pedestrian street.
http://maps.google.ca/maps?hl=en&q=L...04828&t=k&z=18
Yeah, I think they are focusing too much on pedestrian connections to Georgia and Smithe. They could make excellent connections to both streets, but then they'd be left with the far more difficult problem of getting people to like walking beside expressways (or redesigning those streets). Those connections won't solve the problem of connecting this area to the existing area of busy pedestrian activity. There needs to be a good connection to Robson.