If you want to be able to run ifconfig as a normal user, you need to investigate sudo. Basically, sudo is a command that allows normal users to run root commands, without being root. The commands they are allowed to run are listed in the sudoers file. Use the man pages for sudo and sudoers for the fine details.
That said, I think you are approaching this in a rather unorthodox fashion and may be giving yourself a false sense of security. Actually being logged in as root, or as a normal user, doesn't affect what someone can do from the outside. Since linux is based on user accounts, someone could gain root access even if you never, ever log in as root. The mere fact that your computer is on and connected to the internet means it vulnerable. So the best way to go about securing your computer is really thorugh more traditional means. Make sure you have a firewall in place and that you know what holes are in it, if any. Also, be sure to understand what services are running on your computer and turn off everything that you aren't using. For example, if you don't use your computer as a web server, make sure httpd isn't running. You can use the netstat -l command to see what services are running and what ports they are listening to. And be sure to head to the Security forum here on LQ. UnSpawn has done a tremendous job in collecting a ton of useful links on securing your system.
It sounds daunting at first, but it isn't that hard to make your system more secure and you have the advantage of learning a ton of stuff to boot.