I'm going to use small finishing nails (1/2" 16 ga) to attach small, lightweight pieces of trim, but the main stuff is all attached with screws. I'm worried about vibration loosening things up even with the screws.
We used a brad nailer to install trim and beadboard (to fasten beadboard to luan panels that were screwed to the ribs). We used drywall screws to put together the divider walls, which we made out of luan and 1x2 lumber. We didn't use a ton of adhesive, really. Anything heavy (cabinets, etc) is attached to the ribs and/or floor with self tappers. We went through boxes upon boxes of various size drywall screws, IIRC.