Keep in mind that on the GT, the rear height is controlled by the computer and the air springs...to lower that end, yes, you'd have to make some changes. On the front, don't know. If it isn't balanced, the headlights may not have enough range to adjust properly, either and dips and bumps may then damage things like the spoiler, etc.
To keep from bottoming out the suspension, if you lower it 2", you have to make the springs that much stiffer. All this for some looks? The stiffer suspension along with the RFT may make the vehicle more prone to wheel and tire damage, not even considering what it may do to the ride.