I think it would be more intuitive to integrate styles in with the manual controls they go with, especially for character and paragraph styles, like so:
-slide the panel left to see the current settings and make manual changes, slide the panel right to switch to a new style.
-When you look at the manual controls, every element has an icon to show that it is matching a style, and another icon shows if an override is applied.
-click an override icon to remove that specific override