Hi Black_Star, these are quite a lot of questions. I'm sure most of them will be answered in the threads LaurieA linked to. About the smooth polygons option: When Smooth poly is checked, the firefly renderer will smoothen the surfaces. If you encounter strange 'balloon' effects with an object, you can uncheck Smooth polygons for this object in the properties palette of the parameters pane individually. This will override the general setting in the render options. You can also try to lower the crease angle (default is 80). Or you can assign smoothing id's with the grouping tool. For a cylinder you would assign two ids, for a box 3.

Le cinéma substitue à notre regard un monde qui s'accorde à nos désirs. - André Bazin