Well, it's sounding a bit like the id software-style console where you hit ~ and the console comes down from the top of the screen, lookinig much like a terminal window. You have a text box at the bottom where you type your commands and you see output on the rest. You hit something like shift-page up/down to scroll through pages of the output.
First off, the keymapping is already similar. It has the concept of an "impulse" (I call them "commands") and a binding. I say make a list of these things and any special requirements for them to be active. Being the server should be implicit to server controls, but turning rain on and off should probably only be enabled if you have the .ini setting MiscDebugMode (or some other) enabled. So far, I can certainly see toggle weather and mouse pointer.
I think omega has some smart ideas as well. Perhaps the ability to arbitrarily execute lua code from the console would be in order. Also, I don't mind his suggestion on how to do it (simply prefixing the text with a special character), although, I'm thinking that a more common command-prefixing character like the forward slash might be more intuitive.
