authoring tool distinctions

I have been  giving some thought to the reworking of the user interface
section of the guidelines. I would like to add to the introduction as
follows:

Principles to consider in making the authoring tool accessible to authors
with disabilities relate to 3 classes of functionality:
1) The authoring tool is a software program with standard user interface
elements and as such should follow relevant user interface accessibility
guidelines (links to TRACE guidelines, Microsoft, SUN, DACX,  Apple, IBM
guidelines)
2) The authoring tool frequently encompasses the functionality of a user
agent or browser and as such should follow the user agent guidelines.
3) The authoring tool has unique functionality as a Web content editor.
Access to this unique functionality will be addressed in these guidelines.

Reactions?

Jutta