The "Contains" section of the "Organizer" tab should be editable, so
to allow easy removal of 
extra formatting which might get in while
editing styles.

How to do it: 

* display it in a 
tree-like structure

For example, default Heading 1 would look like:

Western
  |
  +--
Font
  |   |
  |   +--Size: 115%
  |   |
  |   +--Typeface: bold
  |
  \--Text flow
      |
      \--Break: page, 
before

* each level of the structure would be selectable
* the dialog would present three 
buttons (Insert, Delete, Edit)
  - Delete would simply prune the branch (remove the selection and 
all
    sublevels)
  - Insert would insert an equal-level branch
  - Edit would edit the current 
selected item

* Insertion/editing:
  - each entry (initially empty in the case of insertion) 
is an entry
    box with attached menu (sorry, can't remember the name; listbox?),
    like the Apply 
Style and Font Name button bar elements, presenting
    in the list all available possibilities 
except for already present
    ones. (For example, creating a new top-level branch in the above
    
example would only allow "Easter" as a selection; a second level
    branch under Western would not 
offer text flow or Font as
    options). They should be "QuickSelect" boxes (editable,
    
autocompleting to closest match).
  - Bottom level entries (like Size: or Typeface: or Break: 
above)
    would have two editable parts: the name of the key, and the value.
    Editing to keyname 
would of course reset the value.
  - Editing is triggered either by selecting the Edit button or
    
double-clicking the branch.