A well constructed system always seems to have hidden redundancies.

As for removable drives, I use a laptop with a docking station and a drive in a removable caddy for a weekly "system state" backup and put it in the fireproof safe. Since it's locked in the caddy, the drive is safe from crushing, and laptop drives are manufactured to survive more g-shock, so beating it up is not a problem with reasonable handling. I use tapes for incremental dailies.