I'm assuming your talking about the gyroscopic tendencies of the turbine? In other words gyroscopic precession. The gyro (the spinning turbine in this case) would act in the direction of rotation and approximately 90 degrees ahead of the point where force is applied to the gyro. Any force. In the case of a helicopter this could cause gyroscopic precession along the lateral and vetical axis'. So if looking at the rear of the heli and the turbine turns clockwise you'll get the following control interactions.

Pitch forward will cause a left yaw.
Pitch back will cause a right yaw.
Both of these interactions would be hidden by the gyro.

Yaw left will cause a pitch up.
Yaw right will will cause a pitch down.
These interactions may be observed. However you need to take the weight of the compressor blades into account. The shafts weight can almost be thrown out all together since its at the center of rotation. Its directly proportional to the amount of observed interaction. It may be so slight you wouldnt consciously register it. Matte of fact, the main rotor may mask these interactions all together due to its own gyroscopic precession. Also keep in mind that these forces would be applied at the inertia point (CG of the turbine) and would dissipate further out since the weight of the heli would dampen the motion.

Moving along, since the turbine is mounted longitudinally, you wont have any coupling intereaction to your longitudinal or roll axis from the turbine.

The tail rotor wont affect roll through gyroscopic precession. First the force applied to the gyro ( the spinning tail in this case not turbine) is equal on all points with a commanded left or right yaw. However a roll left will cause a pitch up and a roll right will cause a pitch down. However these forces are so light, and applied so far from the CG they wouldnt or shouldnt cause a noticeable interaction.

Torgue tendencies of the turbine may cause the aircraft to want roll in the spinning direction of the turbine though. However this intereaction would really only be evident at low airspeeds and high rpm, and again the main rotor's gyroscopic precession would help null this out. Or should if the aircraft mechanics were properly designed.

When the rubber meets the road from a physics standpoint, the turbine's affect on aircraft stability is negligible or non-existant. They should in no way affect the aircrafts ability to perform 3D.