Huf67-
It looks like Don’s light is off so I’ll butt in here and maybe I can answer a couple things until he gets back.
I am confident you can do what you desire with the two videos and it is not a difficult task. Don’t get concerned abut the transitions. Don was not saying you can’t use them, just that if you do it wrong with multiple video tracks then you can screw up the sync of the movie.
This brings up a good point that Don mentioned, save often. A common practice is to save your project with a name like MyMovie. Then periodically do a project Save As and give it an incremental number such as MyMovie001, MyMovie002, etc. If you don’t like what is happening in the current edit, you can always revert to a previous edit and continue on without having to redo the entire project.
As I read it, the crux of the matter is that you want to synchronize two video clips, use the audio from one and jump back and forth using the video from both?
The first thing to do is place the video with the best audio on the primary track. Then place the other video on the overlay track, as Don said.
To synchronize the two clips, I like to apply Picture-in-Picture to the video on the overlay track. I then adjust the size and or transparency to suit my needs so I can see both clips at once in the preview window. Now adjust the right/left position of the clips so both clips are in sync by moving the appropriate clip right or left. I use visual clues such as a camera flash and audio clues such as speech where I can see lips moving. When using audio clues, I alternately turn off the sound on the tracks using the little speaker icons on the right. Once the two clips are in sync, I would make this a save point. I would also do a check at this point to be sure the two clips are in sync from start to finish (make sure one camera was not running at a different speed than the other).
You could also use the audio recording if you desire by using the same principles as above.
Now that the videos are in sync, lock the video on the overlay track using padlock on the right then delete the unwanted audio track from that clip. Or, you could also just adjust the volume of that track down to zero, same effect.
Lastly, switching between video sources. This is how I do it, others may have a different method.
Make sure all tracks are unlocked.
To delete a section from the overlay track. Select the overlay track by clicking somewhere on it. Move your scrubber to the beginning of the section to be deleted and place a cut. Move your scrubber to the end of the section and place another cut. Then right click on the section to be deleted and select "Delete".
To delete a section from the main video track, do the same as above except lock the audio track first and unlock the audio track when done.
At this point I would do another SaveAs.
I then output this project as a file and start a new project using the output file as the source. It is now one continuous file and I can place cuts, add effects and transitions without worrying about whether I am going to screw up the sync because I messed with the wrong track.
ADDED: Hi Don, you weren't gone long. I'll just butt out now.