Remove everything you don't need - cups, pcmcia-cs, bluez-utils, isdn4kutils, ncsd, psacct, NetworkManager, netdump, kernel-utils, nfs-utils, portmap, tux, xorg-x11-libs, rhnlib, redhat-artwork, cups-libs, gamin.
For a DA system, remove other installed packages that DA will update itself.
then yum update.
I always leave in a local IP too, it doesn't hurt and its always easier when/if you have to bring it home.
I also do everything using ssh with key auth the moment I can, even on my own network - last thing you want is not to be able to connect once its far away.
I also install the firewall locally and make sure I can connect with my home IP.
I also install webmin just in case SSHD fails.