Let me try to get this back on track.
Query: What are 5 core functions or commands necessary or desired for a MUSH?
Next Query: For each of the 5 core functions, how would you envision them in a non-telnet (command line) UI format?
I'll start this exercise.
1. say/pose/emit
This is essentially the same command: you are projecting text that others in the same room can see. For a UI, I'd like to see a button that pops open a window you can type into. Once you're done typing the message, you click a button on the window somewhere that closes the window and projects the message on my main window (let's call it 'the Screen').
2. moving/exits/rooms
Ideally, when moving from room to room, I'd like to see a description pop up on the Screen, which will also show who is in the room. I'd like to abandon the traditional exit-to-room-to-exit-to-room way most MUSHes use; instead, have a drop down list or new window of All Public Rooms, and simply pick which one you want to go to.
3. bulletin boards
I like the idea of simply using forums. They are complex enough to handle any task that they are used on MUShes for. The end.
4. mail
Something like a normal mail browser would be simple and easy to use, and appealing. Hell, you could just have people use Gmail, with the benefit of having functions like GoogleDocs and GoogleSchedule.
5. generating a character
Honestly, the best way to do this is send some sort of document or form to staff, and let them generate the character for you. Using a wiki, you could set up a bunch of templates that people can select to start with, and just add additional freebie points or whatever to customize. All someone would have to do to make a character would be to point out which template they wanted, where to put the "free" points, and submit a request to staff.
Just some ideas.
If a game where to implement these, or had a UI that could handle what limited UI functions I've mentioned, then I'd be more than interested in checking it out. We've already determined that I have no interest in learning to code everything up, but implementing these policies for a game might lower the barrier of entry into MUSH-style gaming considerably.