Good advice, except the "remove all system passwords" part. Do not do this. It's a really bad idea. There are occasions where you do need to authenticate using

Good advice, except the "remove all system passwords" part. Do not do this. It's a really bad idea. There are occasions where you do need to authenticate using a password, most importantly on the local console - what if your server lost network access? And that sudo workaround is bad since it requires agent key forwarding, which you shouldn't use for the reasons the author himself noted a few paragraphs up.