From your conf/logs, it looks like you are pushing an RTMP stream to teststream application, and then connecting the output RTSP stream to the test-record application via MediaCaster. Do you only notice the audio/video sync issues in the recordings? The live stream playback has no audio/video sync issues?
Unfortunately, I have not been able to replicate the a/v sync issue using a similar setup (but without using VMix). When using FMLE or Wirecast directly (without using VMix), do you get the same issue?