I use a remote back up service for my computer, but I do not include my password files in my back ups because I worry that if someone hacked the backup software, they would get everything.
I keep a back up of passwords on an an external hard drive that I keep at home. I also have an encrypted copy on a secret drive on a remote server.
I was thinking about storing a print out of my most important passwords in a safety deposit box, but I am not sure how safe safety deposit boxes really are.
Of course, it is also possible to encrypt strings of text before printing them out.
It is best to limit the number of backups you make. Just make sure one is remote.
I would worry about using external back up programs because it is super easy to accidentally expose the data on an external back up drive.
Sounds like a good system you have.
Yes there is a potential downside of having many backups in that you increase (a little) the chance of one being found. A remote backup though is a good plan.