This brings up an interesting behavior that Mike and I were discussing a little while back. With multiple component instances, there is no parent-child relationship among them, so as you said Jeff a change to one, changes them all. However, in a copy-paste of a body, the pasted body is a child to the original, such that a change to the original will be reflected by the child(ren), provided the change(s) to the original occur in the timeline before the copy-paste events of the children (note some changes don't have timeline events, such as driving sketch changes or push/pull, so these types will always be reflected by all children). Conversely, changes to any of the children are not reflected by other siblings or the parent/original. We were talking about this in an idea post here:
http://forums.autodesk.com/t5/fusion-360-ideastation-request-a/mold-cavity-shrink-within-combine-com...
where one instance this behavior comes in handy, is making a copy of a mold that needs to be enlarged a little bit from the original.

Above, the original on the left was copied and pasted, then the pasted child was enlarged, and a hole was then added to the original, yet placed in timeline before the copy-paste. Below Mike shows an enlarged copy of a part, that again has changes reflected in it from the original.

As to using these multiple parent-child linked bodies to make drawings, one method that appears to work pretty well is to do a soft delete/Remove of any bodies in a component that should not show up in a drawing. Once the drawing is made, these bodies are returned via deleting Remove events in the timeline.
The versatility of Fusion is great!
Jesse