Short answers -- no and no.

That said, to answer with more detail:

Question 2:  I often render draft versions of shots to make sure timing is working properly -- it's a pain, but it's also pretty quick.  I'm doing 1920X1080 24FPS  sequences, and dropping the resolution by half (960x540) and using the draft renderer (gourard shader? I don't remember and am not in front of Carrara right now) I've been able to render out scenes in near real time.  It's not quite as easy as Poser in that you just click play and see something not working, change it, play again....  But it does work.

Question 2:  Oh, how I wish there was a shy switch in the sequencer like the AE timeline.  Unfortunately, not.  But I do collapse the items so that my characters take up only one line of space when I'm not animating with them.  And I group things frequently so I can minimize the amout of lines on the sequencer.

Hope that's helpful.  Carrara is a powerful program, particularly for the price, but it is missing some professional elements like these.

 - Dex