Welcome to FTE! Fantastic first post btw.
IMO, if you exceed any of the weight ratings on a vehicle it's an issue. I personally believe that these trucks are under rated a little but the posted numbers really cover Ford's back side.
If you were overloaded / over weight and you suffered a crash and the local authorities decided to weigh your rig, you could be in big trouble.
SCPO United States Coast Guard Retired
2011 F-150 XLT 4x4 Ecoboost
2010 Ford Focus: Retitled to 2LT Sarah Seekins
2004 Expedition XLT 4x2