Cutaways in new iMovie 10.0.1 for OSX 10.9

How do I make a cutaway in the new iMovie that comes with OSX 10.9? I have three separate clips I want to toggle between. I have one on top of the other like is suggested in "old" iMovie tutorials, but I can't find a way to add on a third, nor can I find a way to keep toggling which is the dominant clip.

Another problems I'm having is that one of the clips was shot on an iPhone, and it has different dimensions than the other clips. When it is selected as the cutaway clip, it's just showing up on top of the clip underneath instead of showing on its own.

Finally, I am trying to get the audio (a band playing) to synch up on all clips. Then I'll mute two of the three. How do I move clips tiny fractions? It seems that the clips are always a smidge ahead of or behind where they're supposed to be.