....now when orbiting in 3d mode, it freezes up and is slow because it is displaying shadows. How can I turn them off?
The shadow controls are in the '3D Window Setting' dialog which is found under 'View'>'3D View Mode'.
To be honest, I expect the problem with displaying the shadows smoothly in real time will be the people models you are using. Turn them off until you are ready to render, as each one has around 7000 polygons and having several displayed can slow even the most powerful graphics card down to a crawl!
The trees & vegetation will also have a lot of polygons too, so turn them off next if you are still having problems with the speed.
The cars are also polygon heavy and could be turned off too.
Hope that helps!