The log exhibits about 1% rendering lag, which means about 1% of all frames are lost within the GPU. At 30 fps, this is about one stutter every 3-4 seconds. It also exhibits 20-30% lost frames due to encoding lag, which means your CPU is not powerful enough to encode one frame every 33ms, which is required to get a frame rate of 30 fps.
You waste a bit of CPU by rescaling 2 times: disable "Rescale Output" in the encoder settings and set Video->Output (scaled) Resolution to your desired final video resolution.
It may also be possible that you can choose the Hardware (Quicksync H.264) encoder for encoding instead of x264. This would relieve your CPU from encoding.