I don't think that author mode should have word-processor like features per se. It should have good visual structured editing features, some of which may resemble unstructured visual editing features, and some of which definitely will not. One of the consequences of structured writing is that style is an interpretation of structure, not something the author applies directly. So I don't think style menus belong in Author mode.

To put it another way, author mode is a place to create structured text without having to look at angle brackets. It is not the place to define the formatting of a document. Allowing the author to manipulate the authoring CSS from the author interface will only encourage them to think they are changing how the final output will look, which, of course, they are not. 

One of the author mode features I really love in Oxygen is the ability to define a forms-like interface via CSS. This gives you the opportunity to make the structure explicit to the writer, hide the output formatting from them completely, and still give them a visual editing environment with no tags.

Mark