You know, after doing some thinking (!), I thought why if I first sync every angle with the main audio track, by filling up with blanks if necessary, export the new synced clips, each and every one to a temp location, then creating a new project where I import only the synced clips to my media library, and where I only use two video tracks, one main,and one temp, where the main track is obviously what I want, and then use one temp track where I add the synced clip, and then align/clip what I need from the temp track and drag into the main track. Then I don't need to struggle to get every single clip in sync on the main track, because it's kinda crucial to have every clip in sync when making a music video where it should look like that the musicians are actually playing the song you're hearing.
I'll try that approach today, and see if that method is convenient/smart...