Late to the party, but in the spirit of the title I'm going to say that nothing needs to structurally change at MSB. What change is needed is cultural: people just have to own up to the fact that MSB is merely WORA under another name. Drop the pretense of higher aspirations. Delusion isn't becoming.
There was maybe once a small window in which a site could have been built that was WORA for adults. That ship has long since sailed, however, and this is really just another in the line of WORAs. With this thread you've not only let the animals escape to run out into the night, you've gone and set the barn on fire and are closing the door on the gutted, skeletal remains of it.
MSB, like the WORAs and SWOFA before it, is a bitch board for the MUSHing community: no more, no less. This is not (necessarily) a bad thing. It merely is. The bad part is pretending that it is otherwise and, now that the venom has flowed through all the veins here, that it could be anything else. The bad part is trying to fit something that is simply not natural to the community as a mold around the same.
Keep MSB as it is. Just start being honest about it.