Updating Admissions Custom Fields and Applying Changes Across the System

I recently went to make a change to one of our admissions custom fields, and was a bit irked by the fact that I would have to retire certain items in order to replace them with an updated version of that same item. It would be great if:

1. Changes can actually be made to existing values in list custom fields.
2. These changes made automatically update any occurrence of the value on any student's profile across the system.

Thanks!