Arya,
Brakes are simple. They heat up when used, and recover by cooling down between uses. The trucks as delivered had plenty of rotor surface area to bring the truck to a halt without warping. Multiple times, actually. So we can forget about the heating up phase when they're being used - they can do that.
What's suspect to me is your brakes ability to recover. If the pads properly retract when you let off the brakes, they'll quickly cool and be ready for use again. If the pads are still against the rotors as is typical of a caliper needing a rebuild, then they not only cannot cool properly, but will actually remain heated from the light friction. Since yours work the first time or two, then start chattering it indicates they're getting heated, distorting and staying hot. So, suspect that something is hampering your brakes from recovering/cooling down, and the #1 suspect would be dragging pads. Check for mud in the ventilation fins on the stock rotors, also. That you have 100 series pads on there may not be in the best interest of things, though I know everyone loves this mod. I'm against it.
You should establish that there's nothing loose like wheel bearings, knuckle bolts (!), caliper bolts (!) or worn knuckle bearings. Then suspect the calipers.
As for turning, I had mine turned once after a mild warp a decade ago. But they were done for me by a personal friend who obviously spent the time determining the absolute lightest touch he could use on the machine. Mechanics today simply don't have the time to do that and just use a heavy hand, taking off way too much metal so they don't find that the machine did not go deep enough and missed a low spot after the machine is done. When that happens, they basically have to do it all over again so it pays to simply hammer them. Not their fault - just the way the business works. So, it can be gently done though obviously any material removed increases warpage potential.
DougM