Difficult for my mind to grasp an entire new system right now.
However, adding/combining some keyword 'standard' access levels in with the current one might be nice.
Example, Windows 2000/XP have 'standard', 'power user', and 'Administrator' in its user profiles.
I think it would be good to have some default words associated with certain levels.
From in game, typing "adduser JamminR root" wouldn't add a,d,m,i,n, but would add abcdefghijkl
Typing "adduser JamminR root" wouldn't add a,d,m,i,n, but would add root minus immune, and one or two others.
"adduser JamminR power" would add flags for kick/ban/slay, but no ent, rcon, immune
You get my general idea now I'm sure.
Oh, in addition, these few keywords would have levels configurable in users.ini perhaps.