Yes, it comes with 1 controller.
yes you can use the xbox 360 controllers on the xbox 360 slim. I use my controllers from my old xbox on my new 360 slim.
Depends on preference. Personally, no
Yes. They will connect the same.
Yes
No, original XBOX controllers do not work for the XBOX 360.
One.
It is 4 controllers on every Xbox 360.
Yes, all xbox 360 controllers work on the xbox 360. (no matter what color it is)
No. You will need to register and buy Xbox live.
As long as you have an internet connection, you can get xbox live on a 360 or a slim.
You can find Xbox 360 Controllers on www.ebay.com or go to a local gaming store.
The Wii, PS4 and Xbox One come with motion controllers. You can purchase motion controllers separately for the PS3 (PlayStation Move) and Xbox 360 (Kinect).