The /media/sourcecoast folder is mainly just css and images. It should be fine to clear out. All of the settings are stored in the database, so if you'd like your component settings to persist then don't manually remove/update tables in the database. If you've done any overrides and haven't backed up any themes or done your own template overrides, then I'd suggest making a copy of those.
That being said, we always recommend backing up your site prior to any install or uninstall (whether for our extensions or any other ones).
-Melissa