Change most/any interface text in context

[Brylie Christopher Oxley]

Hi all,
This is a general idea about UI customization and usability. It would prove useful, for several use cases, to be able to edit any visible text through the CiviCRM UI, in such a way that specific pages can have individualized changes -- possibly including the use of tokens.

This is a large, admittedly vague, idea, so I am also working on some example user stories. Please add user stories that you think would benefit from similar functionality.

General idea
In general, end-users/clients interact with the UI on a daily basis. Their primary conceptualization of the software is based on the UI, and many of their suggestions for changes will be based on visible UI elements.

Stories
As an end-user/administrator
I need to be able to modify any user-facing text,
so that I can customize the interface for specific organizations

As an admin,
I need to make word replacements on specific pages,
so that those pages make sense in the context of a user flow (e.g. subscribe to magazine)

As an admin,
I would like to make word replacements directly from any given page,
so I can see how my changes from an end-user perspective in-context

[Dave Greenberg]

These user stories should be part of the design discussion for CiviCRM 5.0 - which will be substantially focused on UI 'flexibility' a la Webforms. One good reminder for me here is that form action controls (buttons / links) ALSO should be modifiable (not just form fields / labels / layout).