i don't suggest you unlink the audio/video, cause, in my humble opinion, that's when u start losing track of your synchronization.
what i think you should do is the following:
- insert your clip in the timeline.
- keep your audio/video synched and watch it.
- wherever you want to add a different video subclip other than the one you have, just overlay it in the video track "above" the one containing your original video.
- this way premiere will play only the video on top, and you don't have to do all the trimming, lifting, overlaying.....
hope this is what u're looking for...
The child has grown
The dream is gone