Dear iMovie User stumped over FC,
I am not a technical genius and this is the first time I have tried to help someone else on this website but I have been using FCP for 3 years. Are you aware of the razor tool? You could take one video file and just chop it up where needed the under one of the headings at the top ( I am not at my FCP computer right now but you should be able to find it)There is a lift button. Do that instead of deleting, then under one of the headings there is an option to close gaps. The audio and the video should always be linked, no matter what cut you make, that appropriate audio file will still be linked to it.
If you want to just select a portion of audio you can mark in and outpoint and on the left hand side, you can lock the video files so that they are not altered. Then you can copy and paste.
I hope this helps.
Elizabeth