Things that will have to be determined by the host:
I did think about trying to incorporate "secret" NPCs into the game to help with the story, but I'm not sure how that would work. What happens if they get rolled as the killer or victim? Then who would help the story, if needed. I was planning on the NPCs to be played by the host(s).
Of course, these are all my ideas and those that are wishing to host their own are welcome to modify and do things their way, however, if you would like my assistance, just let me know. I'm more than happy to help create a map, help with characters, upload the map, post some sort of information on this website for your game.
Some games may be able to be solved in one playing time, but it is possible that some elaborate ones might go over a few or even several. So, try to keep in mind that the more characters, the harder it might be to carry out successfully because not everyone will be available all at the same time. On the other hand, not enough will not make it challenging and fun enough.