Idea isn't unworkable as we've done a nearly exact same thing before, only players didn't volunteer to join to be killed, and the killer isn't restricted to a quest list type of approach...
What we did back then was that a bigger part of the arc is that Dracula was out murdering people at night, and players have to guess who's Dracula's identity at day time. Dracula (the mvp) attacks the victim at night time if the designated killer is in a non-exp loss town. There was no explicitly given hint except the goal being to find out who's Dracula at day time and that Dracula is a "real player." What Dracula did was that during some night time he only targetted females in guilds that tried to recruit Dracula's daytime identity into their guild (following the novel's principle on who does Dracula attack), and players who figured out the common points in all the attack is able to greatly reduce their search to pinpoint out which guild did Dracula belong to. Finally, Dracula's daytime identity is named "Stoker" in honor of the author to the novel, thus there's sufficient hint to find out exactly who it is. So in a sense, that's sort of like your macro plan in plan B for RPing.
I just didn't do it again for reusing same tricks in a large RP arc XD;