This is the best laid out argument I've seen on the subject, and it's almost convincing. For me, it's just not quite convincing enough. I think there is an overestimation of the net profit from selling Wrigleyville properties. I think there is also an overestimate of the potential for additional revenues from non-baseball use of the stadium. Allstate Arena, Sears Arena and the Stephens Convention Center are already under booked (although less so for Allstate Arena). I also think that Parking would absolutely be a huge profitable benefit to the land owners, but I think part of any municipality's offer is going to include significant profit-sharing from parking concessions. Finally, I don't like the Mesa comparison because the facility is a year-round use facility.
Again, it is a very convincing argument that when you subtract the unrealizable profit from the attendant expenses of a new ballpark, moving is not nearly as financially implausible as one might think. It's a point I haven't really considered before and I appreciate you laying it out in the way you did, but I'm still not convinced, even using your numbers, that the Cubs wouldn't be substantially better off staying in Wrigley Field, renovating (er expanding) it in the way they plan, and building a winning team. But I now have a different way of looking at things to think that if they can't do that renospantion (expavation?) exactly the way they want, maybe moving isn't such a bad idea after all.