Borate, thank you; you are amazing! This is exactly what I needed! Can you tell me the steps you followed? What I did was: unlink the video-audio tracks and drag the audio where I want it. But then I right-click on audio track, click Restore Linked Video, and the video snaps forward to meet the audio track. Or if I right-click on video track and click Restore Linked Clip, the audio snaps back to meet the video. I have tried holding down “ALT” or “SHIFT” while dragging; same thing. The same thing happens if I go to “Clip Preview” and click “Relink”. I finally figured out that if I highlight both tracks on all clips and click Menu > Sequence > Group Selected Clips, it will stay put, but I don't think that's how it should work. Various other insanity was occurring, like the video snapping to beyond the audio track, but I expect that if I know the proper procedure I won't have that problem.
Re the noise--I am puzzled. When I play the two "Everybody"s that I attached above, in the 2nd one the speaker definitely begins with "NOW, ..." rather than "And now ...". And if you listen at minute 00:18, the actor says "What is that laughter and to whom does it belong?" followed by a loud rumble in the 2nd version, which is not there in the first. The extra noise continues throughout, for me, but that is an easy place to spot it.
I do have version 9.04. I am using Windows 7; will the version you recommend work on it?
I forgot: you had inquired about the original Zoom recording. I will attach here the one I used for the first of the video, through minute 03:25, and again from 04:21-07:52. Other than that I used pieces of other recordings. https://drive.google.com/file/d/1Y1Byhc77E3VmQgjbpQXC2fiH9AqZtulV/view?usp=sharing