Originally Posted by MrSelfDestruct

1: Ideally, the transmission should be tuned so that if the torque curve were to be plotted out, it would form a bell curve, with the ratios set so that each shift would take you from the graph's upper point of inflection to the lower point of inflection. This would keep you in the torque band the whole time. For practical everyday driving, you should shift as low as possible. For maximum speed, you should shift so that you begin each gear near the peak torque.

2: Your cruise control does not apply the brakes, it can only control the throttle.