Attached Link: http://www.aprilgem.com/log/index.php?p=336

Yep, no shadow passes. The best way I've found to isolate shadows is to render everything untextured so you get the shadows on smooth gray surfaces. Then in Photoshop, you can sort of use what you've rendered as a "Multiply" layer -- with anything NOT the shadow(s) being masked out. So you know what I mean, I'm attaching a link to one of my WIP/tutorial pieces, where I rendered an untextured scene to help me add shadows to a scene. Hope it helps on the shadow part of your composite piece. Everyone else already answered the other parts.