Type a passphrase to link this device. Use the same one on every device — it's what scrambles the data before it leaves, and it is never sent anywhere.
Unlinking keeps everything on this device; it just stops syncing.
A buzz at 9 AM the day before anything with the bell switched on. Needs sync to be linked (the passphrase is what unscrambles the reminder text). On iPhone this only works from the home-screen version.
Export makes a plain file of everything (not scrambled — keep it somewhere private). Import merges a file back in.