JackG-
Not trying to start a debate about all the exact #s.....
Instead, I'm simply trying, for safety sake, to show how a lot of people who want to haul things get into trouble. The crux of the problem is not understanding where the #s come from and the capacity of the vehicles they are using. You'd be surprised at the # of people who just look a the hitch and say, "hey I've got a 6500# rated hitch so I must be able to pull that much".
Agree, 500# in misc sounds high but most often, mfgs (especially domestic) use the stripped down weight of the vehicle to calculate max towing capacity. So, when you add in third row seat, rear a/c, sunroof, dvd players, 3.73 axle, weight distr hitch, plus your true cargo (cooler, bags, picnic chairs, etc.) it can easily hit the 500# I sighted.
But, yes the wheel base is an inhibiting factor too.
As for brakes, I usually get about 40-45K out of a set of pads/rotors here (since they beefed 'em up from 1st gen Explorer). My terrain in western PA and WV where I do a lot of driving is substantially different than in SC. Not to mention climate and all the rock salt used in the winter pays a much heavier toll on my components vs yours. So it's really not anything different I'm doing than you, more environmental.
Again, I'm not bashing the Explorer as I currently still own the '04 and have had 4 previous ones.