cutting a multicamera project in xpress dv 3.5

Hello there, I am a guy who usually edits in a Discreet edit or premiere, but now I got a project to do on a xprees dv.
I have materials from two cameras , I have synced both, one is on video 1 other is on video 2 I added a PiP effect on a upper track so now I can see them both playing together .What I want to do is to go through whole video and add locators on a points where I should switch a camera.But I can not add a locator on a timeline ?? Secondly when I find a place to edit - on a timeline, I want to split that clip on a timeline and paste the contents from the upper track to a lower one.What should I do to split a clip on a timeline? Third , I would like to see an audio waveform - I press "sample plot" on a fast menu of a timeline and - nothing happens. The audio is still lightly gray. Audio levels are okay - so what is wrong?
That`s it probably I would stick to what I already know instead of trying to discover new land.
Thanks to anyone who will reply.
It was a long hard day........
Kicki