Spent all day Monday (12 hours) and 10 hours today syncing and re-syncing the audio for video 3... still working on this and definitely testing my patience to new levels. I've succeeded three times only to export the file to video format and have it not synced... no reason why. Have give three different workarounds a try and none of them have worked.
Now I'm dropping the video into iMovie and seeing if I can edit the audio and video files together there... amazingly frustrating spending so much time on something and not producing a finished result.