Trouble with racks
 

I bought a pannier and rack combo from Nashbar. Checking out the fit before installing on my Fuji World I noticed the rack width is at least 1.5" narrower than the frame [measured at the mounting spots]. It's actually almost the width of the front hub/fork. It does have the shape of a rear rack (don't know about front racks) and a bolt on area for a rear reflector.
Has anyone seen this before?

On the same subject (but for a hybrid) it seems two other racks (old takeoffs) have sizing issues. They are both slightly too narrow than the hybrid back hub and too short to reach the mounting points. The racks end up sitting on top of the fenders. The hybrid does have some tall a$$ bontrager tires.

This is normal. Attach one leg loosely, stretch the other leg to the other dropout and attach. After you have done this, the top attachments and adjustments are easy to make.

On your second point, if the racks were made specifically for 26" wheels, you may have to purchase a different rack to accomadate the new bike if it has 700c or 29" tires.