How to cut part of the timeline in Character animator?

Oh, you can also use a workspace window to not modify the scene, but specify and start and end point within the scene. You can then export that range to a video clip. You can only have one defined per scene, but i frequently use that to fine tune the subset of the scene to export. And yes, i generate clips just for the bits i want and just use prem pro to concatenate the clips (no trimming). It reduces the render time too! 

Or, you can just change the Duration property of the field and shorten it. Sometimes I trim the front off a scene however to let hair dangles settle down, which is where the workspace range thing is very useful - internally it renders the contents before, just does not write it to file, so all the dangles for long hair settle down

Yes, you can duplicate, trim and splice etc audio takes in Ch. It does not modify the audio file - instead the take remembers which part of the audio track you want to play. So if you trim it short (grab left or right edge and drag it), then drag it out longer again, the audio is still there. If you duplicate a take, it just has two references to the same audio clip internally so you can just trim them both to the subsets you want.