If you want to backup important configuration files then I would use an include file. Although probably not syntactically correct it would look something like this:
# cat /root/rsync_backup.lst
Then use the include-from option to specify the absolute path of the include file.
# rsync -vrlEpoght --stats --progress --delete --include-from=/root/rsync_backup.lst
Once you get everything working, you can use cron to back them up as often as you'd like. You can also sync them to dropbox if you sync them to a directory that dropbox is watching.