maybe a multi level system would be better, superadmin and admin

Superadmin being the server owner
Admin being an admin who logs in via password

and maybe the admin can assign an assistant admin

or superadmin can assign admin assistant, something like that.
Would be exceptionally useful for busy public server

just note that you have unlimited number of admins using BE's RCON

ingame UI administration is sort of unfeasible anyway ...

so while it's not optimal to have just one admin via ingame UI
it's not end of world

B3 (bigbrotherbot.com) allows multiple players to admin whilst in game, and can restrict command access to different admin levels.

How nice of you to advertise here.

@Dwarden
thats true but as most people are not "smart" enough to connect using RCON there needs to be a solution around

it also would be nice to add very own chat commands (all that in combination would make it possible to develop a real admin interface for arma by the community)

As it IS possible to use RCON for multi admins
what about event handlers for chat?
that would make it possible to redirect the chat command directly to a modification instead of arma so that the modification can connect to RCON directly using (for example) a c/c++ interface

the eventHandler could look like

add-/removeChatEventHandler[<HandlerType>, <Code]

and have 2 handler types:
Chat - Triggers everytime when the chat was used (text commited using ENTER) & awaits a BOOL as result (false: continue using ArmAs default implementation; true: stop ArmAs default implementation as the scripts implementation was used)
Command - Triggers everytime when a command was issued & awaits a BOOL as result (false: continue using ArmAs default implementation; true: stop ArmAs default implementation as the scripts implementation was used)

greets
X39

PS
a markup plugin would rly be awesome for this mantis tracker ... makes formatting much easier (bbcodes would also be acceptable)

This is really annoying, as I want my buddy to be able to type inits into objects VIA zeus when I'm not around. If I give him the admin password then I can't do anything myself when he's already logged in.

You can execute serverCommands via script now.. And you could do that simultaniously on multiple players.