Help - Restrict root privileges - What is indispensable?

[Manuel Gomez <mgdpz1@gmail.com>]

Hi, i would like to restrict the privileges of root. Now goes the
question: why?

I only need the essential for run my OS:

Can access to my frontend netfilter (iptables) shorewall.
Use chmod, run sh scripts, and any command essential for running the OS.

I would like more security, and i have to open gksu constantly, so i
have chossen this. I not going to use sudo because Shorewall doesn't
accept using it as a normal user.

How could I change /etc/sudoers?