OK was interested in your issue as well and the very first thing that I noticed is that it is not the fastest model, for what kind of model it is.
I also get the wonkey shadows, so as Aaron says, not your hardware it seems.
One thing that could be part of the issue is that there are 10398 Warnings in your model, with about 2000 walls overlapping and about 8000 identical instances in the same place.
Not a 100% sure, but lets say 95% sure that this is causing all sorts of problems.
Looks like there are A LOT of curtain walls that are duplicated in the same place, which I guess happened with groups in groups that you arrayed and those you arrayed again.
Then there are the levels in the 3D view, I have never seen those in that weird way, where they seem to be all over the place