Yes it will fit.
Yes
An alternator from a 2000 Chevy blazer will fit a 2002 S10 blazer with a little fabrication.
Will a Chevy blazer engine fit in a Chevy s10 pickup
Will a Chevy Blazer engine fit in a Chevy s10 pickup
Yes
Yes
No.
any s10 or sonoma up to 93 and any blazer jimmy up to 94
Yes
if it's out of a 95 blazer it will work
Yes. Very easily. They are built on the same body, but the blazer is the suv and the s10 is the truck.