I think Ragtime would sell very well at the Muny, of only because they could easily throw the Muny Kids and Teens into the ensemble. Those kids sell a lot of tickets, just with family and friends coming to see them.
And I would disagree about St. Louis audiences being unwilling to try something new. Take Stages for example. The past few years their best selling shows have been their more "contemporary" productions, i.e. Footloose (2005), Grease (2006), Full Monty (2007), and Joseph (200

. Yes, they have a much smaller space to fill, but their subscriber base is not that much different from the Muny's in terms of demographics.
I will add that while Paul Blake does plan relatively "safe" seasons, he knows what he's doing and you can't fault him for that. He keeps a lot of people employed and in these times that is a damn good thing. Plus, as I stated in my previous post, I greatly admire the Muny's dedication to using the full original orchestrations. You will never hear a reduced orchestra there.