Hi
Yes, you are right that windows present an issue for good lighting conditions. Also I'd mention the glossy floor as another issue as it's an issue for a proper background subtraction.
However, I believe the main reason for your tracking is not adjusting the colors of an actor model to match actor clothes. I see default colors on your screenshots. Please read
this section of the User Guide thoroughly.
As for camera placement, please read
this section. The minimum distance between a camera and an actor is dictated by the rule "an actor should be fully visible at all times". Thus it depends on the height of an actor and kinds of motions, but usually is 1.5-2m for PS Eye cameras.