+1 on the very little front brakes, if you watch Drakes youtube vids he addresses this and says especially in the truck that he doesn't run much front brake.
Also on the rear diff stress issue, if your diff is shimmed properly and everything is correct you should be able to run as much rear brake as you want, I would think a snappy clutch would apply a lot more stress to the diff then too much rear brake.
I also agree that you shouldn't have to adjust the flight of the truck in the air if you leave the takeoff correctly.