Yes, your data is backed up nightly with 3 trailing daily backups. In the event of a system-wide emergency, we will be able to restore your data to the most last previous daily backup with minimal data loss.
We are using Pingdom, NewRelic to monitor the statuses of our servers. As soon as the site goes down, we will be able to react quickly to recover the issue.
Your sensitive data (password, etc.) are encrypted 1-way with sha1 algorithm and your own unique salt, so that no one would be able to see your data.