Hi Chris,
the main.css file I sent above is only for the app, not for browser. In browser the theme in your Moodle site will be applied. They are different, the CSS of the site doesn't apply to the app and the other way around.
The point 2 is correct. You only need to include the parts you want to modify.
We don't have any list of objects for the app. The example you provided is part of the Ionic CSS, it isn't used in the app. Ionic is the framework we use to build the mobile app.
You can find a bit more info in here:
https://docs.moodle.org/dev/Moodle_Mobile_Themes
In general I recommend you to use the webapp to run the app, inspect the elements you want to modify and check which classes and styles they currently have.
Cheers,
Dani
