Brake Drum Wheel Cylinder problems of the 2012 Dodge Avenger

While driving through the mountains in maryland,I applied the brakes and the entire car shuddered. The rotors were apparently warped and the car was difficult to slow down or stop. The more the brake temperature increased the more difficult it became to slow the vehicle down. Most of the mileage on the car is highway or country roads, as I live in a suburban area. The brakes still act up in flat areas just not as bad as they did in the mountains. I have a six speed 2. 4l, 4 cylinder in the Avenger. Before and after having the transmission flushed the transmission would downshift hard between 3rd and 2nd gear and 2nd and 1st gear. When I backed out and put the car in drive, if you didn't wait for about three seconds prior to accelerating the transmission would slip then bang into gear a take off. The entire transmission was rebuilt but you still have to wait for it to lock into drive before taking off. The transmission was rebuilt with 36,000 miles on it.