iCloud is not a drive you store your data on. iCloud syncs data and changes between your devices. So you have local copies of a document on your iPhone and Mac. Make a change on your Mac and it will show up on the iPhone. Both devices have local copies. In other words you will always have your data.
The only things stored on iCloud are device backups and iTunes purchases.
Addresses exportable as vcards, as noted above. Mail has export options for mail boxes and individual mails, plus icloud is using IMAP, so you should be able to export both from the server and the client.
The only things stored on iCloud are device backups and iTunes purchases.