Backup Strategy
1) Local Onsite Backup - Rapid Recovery. Virus or server goes down. Current method of backing up to external drives is good.
2) Local Offsite Backup - Flash Drive method is good. Or you can actively restore from part 3 to a computer at home or something.
3) Remote Offsite Backup - You can continue to use Carbonite. Backup database without II or Sigs to Carbonite. Let Carbonite backup the AC folder II and Data001. This will keep bandwith usage to a minimum.