can i use a front seat from a different gmc model in my gmc canyon pickup?

Chevy Colorado or Blazer seats will work.

Sure as long as it fits within the space provided. You may have to do some modifying of the mounts. You could use any seat from any model as long as it fits. Ford, Dodge, Toyota, etc. 

You can if you can get it securely mounted and safe to use with seat belts.

Who knows? Depends on the year and model it comes out of and the year and model it goes into, dipstick. Next time, try to ask at least a semi-intelligent question.

You can do anything you want if you live in the greatest country ever... AMERICA