Biggles, your troubles are all rooted in the in how the transition to the new terminal is being handled (more appropriately mishandled).

The original concept was for the central hall to be built very quickly after the new terminal went live. This is why there are very little retail/food shops in the new terminal and security doesn't "fit" within the design concept. The central hall is in the same location as the old US and Canadian Customs processing facilities, so construction could not begin until after new terminal operations began.

In order to defer spending, the airport authority decided to delay the central hall construction for several years (original completion was fall of 2001).

For AC, this has resulted in a huge problem because the transition phase did not have commuter gates attached, therefore Jazz had to be located in the old terminal. However, the new terminal was designed to be able to handle widebody aircraft more efficiently; therefore the mainline side had to relocate to the new terminal.