Rod bearings aren't affected by bumps in the road.
The valve noise you are hearing is most likely not valve noise. Use a mechanic's stethoscope to listen to the valve cover, and it will most likely be quiet. Listen to the intake manifold, and you'll hear the noise. That's the tumble flaps. If you do this diagnostic, and find what I wrote, then start a thread asking about tumble flaps.
CV axles don't typically cause stuttering or stumbling like you referred to. Vibrations can be caused, but it's doubtful that those would be severe enough to seem like the engine is being affected.
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Originally Posted by the user formerly known as ZX3_Chick
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