In Gothic 2, I've been having this very noticable issue where the camera keeps stuttering and shaking every time I move. I have the player kit, system pack and widescreen fix installed, have the game set to borderless windowed, and the only other mod I have is the g2classic mod. The framerate itself doesn't seem to be dipping, the camera is just acting jittery whenever I move. Has anyone else had this issue?

Does it only happen when you are going forward or every time you pan the camera ?
Easy way to test would be to try playing with a controller, see if it stutters still.
If it always happens to you after the same, regular amound of time after pressing a key, could be that the game doesn't handle key repeat properly; I suggest you try going to your keyboard settings and change the repeat rate and delay to the lowest setting available (Keyboard -> Speed, then drag the repeat speed and delay sliders all the way down).