I suppose cutting and pasting could help - but the issue turns out to be a bit more complicated - in order to time out the animation to the duration of the audio, what I really would like to be able to do is to put all of the pictures on the timeline, and divide up the total runtime of the audio evenly with the pictures.
1 - I guess I need to convert each jpg into a symbol? Is there a quick way to do this?
2 - Once I have the symbols on the timeline, I'd like to go ahead and do the basic scale (zoom) and crossfade animation for each one, then arrange them one after the other on the timeline, and then...
3 - Select all of them, and drag them on the timeline so they all scale proportionally in length to the total length of the audio track.
Does that make sense? Is there an easier/better way to go about it that I'm missing?