If I set a variable in /etc/environment, it only seems to apply to administrators while in sudo su.
How can I get the variables to apply to everyone? Especially when they are in terminal?
One way to do this may be to add the variables into /etc/.bashrc (assuming everyone is using a bash shell)
If you want to setup variables to apply to everyone, the best place is neither /etc/environment nor /etc/profile, because they are system files -- messing them up will give you headaches when you system is upgraded.
That's it. When you need to have similar setting on different boxes, or when it time to do a brand new installation, or any similar situation. Just backup/copy the file over, and you are done for the day.