I think in suspense novels, the obvious villains usually end up being the villains, but I don't think that generally holds true for plain mysteries - or at least not golden age ones; I probably haven't read enough modern mysteries to generalize.

But in golden age mysteries, the authors are trying to stump you, so usually the obvious villain is a red herring although I suppose a particularly devious mystery writer might fling up an extremely obvious villain just so experienced mystery readers will go COULDN'T POSSIBLY BE HIM, MUCH TOO OBVIOUS... and then it is him. No one suspects the devious foreign count with a mustache that he literally twirls!

Also weeklong murder mystery dinner theater is a glorious premise for a mystery novel and I applaud Francis for deploying it.