I'll open the discussion on "One Paragraph, Three Ways." I found the conclusion quite provocative: "you will neatly sidestep an issue that often troubles novice copyeditors: 'How do I maintain the author's style?' That issue will not arise if you focus on copyediting—not rewriting—and if you explain problems to your authors and ask them either to resolve the problems or to select among the alternatives you are posing."
It could be true that, most of the time, beginning copyeditors will not have to be concerned with an author's style. However, sooner or later, they will be editing someone's work and will come across a sentence or a passage that needs revising. At that point, they will have to think about the author's style and how to fix the syntactical or logical problem without disturbing it.
Let me add that in our office there are many kinds of copyediting. We don't only copyedit the work of our authors. We also copyedit catalog text for our publisher, UH Press; e-mail messages to authors that need to be diplomatic while explaining fairly complex matters (my boss and I send such things back and forth to each other); procedures for our staff; grant applications and reports; promotional materials, such as information sheets, flyers, and ads; fund-raising letters; and so forth. Sometimes these materials require a certain voice or style.
Of course, junior staff members usually don't work on these things; however, we will occasionally give them a small writing task or ask them to review grant applications and reports. For example, we recently asked a graduate student on our staff to work on catalog copy for UH Press. She drafted the text after my boss explained to her what he felt was special about our forthcoming issue, which pieces he especially liked and why, etc. A creative writer, she was sensitive to what he was saying and how he was expressing his feelings and thoughts. She came up with something quite unusual. My boss edited it and then gave it to me. I did some significant editing to a few parts, and he edited the text again. After all that was done, some of her contribution still remained. We were all pleased with the results.
Of course, there is always tomorrow, and it's likely that the copy will be edited again :-)
P.S. I want to point out that in the first paragraph of this post, there is a quotation within a quotation. You use double quotation marks for the enclosing quotation and single quotation marks for the enclosed one.