I take it you have your imported items in your .enc file. How do you back this up over the Internet to AC? It would likely take a long time.
First, while it makes good sense to back up to your local computer and then back that up, it seems to be causing issues, so I would stop and just back it up either directly to the NAS or the 1TB backup. I know 5GB would grow, but right now you could back up 200 backups to the Terabyte drive.
I would also back up the imported items separately. They could be backed up to the NAS or TB drive.
I don't see where manually going in and deleting backups is an issue. Probably 75% of the backup world do this.
All of my backups are set to have the last backup deleted in a certain time frame.
You could use Jungle Disk to back up offline for just the data.
Since Memeo backs up in different places, have it back to the NAS and the TB. If you back up the Imported Items to those two places plus Jungle Disk, and back up the small .enc file to the computer and then to NAS plus offsite, you will be offsite.
Remember, the imported items are helpful to have three months worth. The AC data is good for about five weeks. You can't go back and grab a file from AC .enc very easily.
Memeo is good backup software. It has the ability to do Continuous Data Protection as well. I looked at the site briefly to see if it could auto-delete, but couldn't find that listed. I would call and ask. It's rather robust.
If not, and it is important to you, then think about different backup software such as Acronis or Paragon.
