Need to know what year Blazer.
Go online to a parts store such as Advance Auto Parts and look up the fuel pump to both vehicles to see if the part number matches between the two.
Yes, the doors from a 98 Chevy Blazer will fit a 2001 Chevy Blazer with a little moderation.
YES they will be the same pumps.
Yes
Fit 96 grill in 95 blazer
Yes, it should fit perfectly.
An alternator from a 2000 Chevy blazer will fit a 2002 S10 blazer with a little fabrication.
Yes.
Will a Chevy blazer engine fit in a Chevy s10 pickup
Yes
Will a Chevy Blazer engine fit in a Chevy s10 pickup
No.