There is only one thing that I dislike intensly about poser (or at least the P4 I have) - the camera systems, each figure has it own camera. Whenever you try to create a multifigure group with interaction, switching from one to the next pops you around view-wise in a truly aggravating manner! Other than that, I find it a useful tool.
I don't think these art sheets are something I am really interested in.
Rendo is a general community now. That means rank amatures to seasoned pro's (and we do have a bunch (at least in the C4D forum)). Yes there are more over at CGTalk but that site is targetted at the professional user.

Pass no temptation lightly by, for one never knows when it may pass again!