While rough country isn't as nice as the more expensive ones it is not inherently going to drive horrible.
However, a poorly installed kit will be.
that looks to be a 3.5 inch at a minimum, maybe 4.5 or more.
3.5 is where you start needed to change the geometry of the suspension system. As mentioned adjustable track bar (You could see if you have one by sanding in front of the vehicle and seeing if the wheels stick out farther on one side than the other. Even with my 2.5 inch lift it is a bit noticeable) and longer control arms. The wrong length of control arms can create problems.
Be a bit more specific on "drives bad". You could just require new ball joints, or those tires could be overinflated.
On the other side, if that is an automatic, 35s on a 3.8 with 3.21 gear ratio, it will feel pretty underpowered.
Just by looking at it it has been modified in many ways. You will have to do a complete look at everything (ask the previous owner) to figure out what has been done. So many things get done to jeeps and before doing more, you need to know what you have.