I am creating a series of "photo" stills of various social interactions among co-workers in an office lounge. Each photo demonstrates a particular kind of social behavior, and will help illustrate a particular social theory. 
I have already created the lounge environment and all the actors (in Character Creator). For each "photo" the actors have to be placed and posed differently, but the environment remains the same. Note that I am not doing any animation, just using the tools of iClone to create the poses and expressions for multiple characters within complex social scenes taking place in the lounge.

My first question is: Should I do this all inside the same iClone project?

I assume I would then have to place all the actor positions/poses on a single timeline, and then render individual frames to take the "photos". My main problem here is that it is terribly easy to accidentally ruin a carefully constructed shot on the timeline while working on another shot somewhere else on the same timeline, since everything is interconnected (e.g. various values that are interpolated over time). The alternative I am considering is a separate iClone project for each behavior example, but then I need a way to easily share the same environment between iClone projects.

This leads to my second question: Is there a way I can re-use iClone environments (and then I mean everything from the props to the lighting and rendering settings) across projects? (other than just keep opening the same project and cloning it with Save As..., since it will then become a nightmare to update all the clones if anything needs to change in the environment).

Any insights appreciated! I am very excited about the quality of the test illustrations I have made using Character Creator and iClone, but I want to make sure I'm applying the best practice to accomplish my goal, before producing the rest of the illustrations.

Thank you very much! :-)