Okay, so I'm an idiot........Just realized after owning my 08 F250 that my hubs were in the manual position. Had noticed some binding on tight turns and some front tire squeal on wet pavement, but never checked the hubs. So I have a few question regarding said issue....
1. How much extra wear and tear have I caused?
2. Why would the PO have kept them in manual?
3. Is it possible for me to feel the difference of the less resistance or is it in my head?

I have noticed an improvement in MPG's. Not sure how much yet.

 

You did not do any harm. If the hubs are locked, the axles are locked to the front wheels, and everything turns when you go down the road. Because you're now spinning the front axles, differential and front drive shaft you will see a slight decrease in fuel mileage. It doesn't hurt anything. Around here I pretty much lock my front hubs all winter.

As to why the previous owner did this? Perhaps the automatic feature on the hubs is not working properly. You might want to test them to see if the hubs are locking properly.

 

Shouldn't be any harm done. But I would get under there and find the zerks in the front axle U-joints, and give them a shot of grease.

 

Wasn't so worried about harm as I waz about extra wear and tear.

 

This is how I found out that my truck would not work by just pulling on the xfer case lever. I went for a test drive, pulled the lever and the 4wd worked and I called it good. I never checked to see if they were locked. My fault.