Good overview.

Yes, accessibility would mean that the user is not prevented from accessing what they should be able to access. This would overlap with general bug fixing and problem solving for the base functionality.

Agreed that usability comes before effectiveness. Effectiveness involves among other things switching between menus and engaging in a work flow.

Visual design: make it appealing and easy to interpret from a user perspective, assuming varying degrees of familiarity with what is happening under the hood.