The first one: people can only be warned by their superiors, if that makes sense. A level 40 can only be warned by a level 40. Most plugins where you can set an autowarning allow you to set a maximum level for that.
The name stealer one, the dupename plugin will give out warnings if they have the same name as the admin, and the nickreg plugin allows admins to register their nicknames, those caught stealing will be warned.
http://www.bigbrotherbot.com/forums/releases/nickreg-registers-nicks/You make people admins by using the !putgroup command. !putgroup dakota admin and the like.