Air Brake Disc Rotor problems of the 1998 Chevrolet Suburban

Brake rotors have become warped twice now, first time at 5000 miles the second at 13000 miles. At 15000 miles it now needs new brake pads. The engine computer will not let the engine idle down until you have come to a stop. This makes the vehicle very hard to stop and hard to control on slippery pavement. Very unsafe. Dealer says it checks out ok on both the brakes and engine idle problem. 95% of my driving is on interstate highways, thus seldomly using the brakes!.