I'm so new at microstock that I feel guilty even responding to this discussion.  I also posted this in the original Collective discussion. The links below are to two articles written by Dan Heller.  These articles are very thought provoking and may touch upon some of the issues that are being discussed here.

http://www.danheller.com/blog/posts/meta-stock-agency.html
http://www.danheller.com/blog/posts/virtual-stock-agency.html

Just my 2 cents!

Gary