My backup/maintenance solution

I think I've finally figured out a good plan to maintain my computer and digital information.

1. Compressed backup of home computer at beginning of month onto a portable external hard drive (Seagate 100 GB notebook drive). Rotate several backup copies on the drive, deleting the oldest copy before writing a new copy. Bring drive home to do backup, then take drive off-site to another location away from home.
   
2. Compressed backup of home computer mid-month on a large-capacity external hard drive at home. Rotate several backup copies on the drive, deleting the oldest copy before writing a new copy. I currently have a rather small external hard drive and I'm thinking of replacing it with a Western Digital 500 GB My Book.
   
3. Once a week: run anti-virus and spyware programs and use rsync to a) backup/update work folders on a work server, b) backup/update pine mbox files from my university email account onto my home computer, and c) backup/update an uncompressed mirror of my home computer on the large-capacity external hard drive. I use ssh encryption when connecting to remote computers. The anti-virus/spyware check is a set of automated tasks (I just leave the computer on). The rsync process is handled by running a Windows batch file which calls a Cygwin shell script. Unfortunately, I can't automate this process because rsync needs my password to connect to remote servers; I'd rather not use SSH keys for hands-off password-less login.
   
4. Every two weeks, backup Gmail via POP access to Thunderbird and also backup information on del.icio.us, Backpack, and Yahoo Calendar.
   
5. Once a month, run ccleaner, chkdsk, and O&O defrag. I run chkdsk with a Windows batch file and manually run ccleaner and defrag (I like to do it by hand since they are sensitive tasks).