Everything related to specific items (like the volume of a recording or the key of a song) is saved in the cloud and will be re-downloaded to your device. Some things in the Settings area are specific to your username (like your document size) and are also synced, but some other settings are specific to your device (like the file download directory) are not synced. So the device-specific settings are the only things you would have to re-enter.
Also, layouts are device-specific and do not sync, but you can email them to yourself to back them up, then import them back into the app after reinstalling.