Yes they can on most Kinect games, but you do need a bit of space!
It is recommended that you have at least 13 ft. of playing space (6 ft. being the minimum, which still works great). If you have a cramped room you may need to do a little redecorating in order to play kinect effectively.
The Kinect for Xbox 360
It is not required; you can play it with the normal controller.
No, you do not need Kinect to play CoD: Black Ops or Halo Reach as both games are not Kinect-enabled games.
Both items above are totally different. The Kinect is an add-on for the Xbox 360. The kinect zoom is an add-on for the Kinect which allows less space needed to play the Kinect.
no.
no you can hook it to a pc
You can always calibrate the tracking, audio, and play space.
Nope
You or anyonw else does not have to or NEED to play. It's your option. Although, I reccamend you do.
Yes you do need an xbox 360 for kinect alouth they are alot i find that kinect is great fun for exercise and just to play as a family. youtube.com/unlimitreflex