Chatsong_ did you get some more specific feedback? It's difficult to provide any suggestion without more details with which areas, menus or specific links cause trouble.
I would not call difficulties to format posts a "navigation" issue. Is this the main complain? Do you have the Markdown extension (and therefore formatting shortcuts) enabled?
Or you mean people have difficulties starting discussions at all? The button is pretty prominent. Is this more specifically about selecting tags?
