A combination of parking & a bus terminal at the Grace Street location could reduce some of the headaches caused by fans arriving at & leaving games. Pulling the shuttle buses of Addison is just common sense - they're not exactly a delicate feature there in the crowd of fans. A Grace Street station would create some order, and make the whole process much more efficient while still being only a 2 minute walk from the stadium gate.
Restoring the city street grid & reopening Seminary Avenue gives the street back to the neighborhood, creating a pedestrian route that is currently blocked by parking fences. The area around Wrigley lacks any true public open space - both this block and the bowtie Marquee Plaza could be used throughout the year for neighborhood events. Put up a Christmas Tree in the winter, bring in a farmers market when the team is out of town, hold a sidewalk chalk art festival along Seminary Avenue & make this new Wrigleyville Block Party an annual event in some way.
Perhaps one of the greatest things that can be done with this block is to simply finish it - to do anything with it. The Triangle Building can finally complete the block and make it feel like less of a seasonal construction site. Yeah a skating rink is nice, but really any version of the Triangle Building is better than the patchwork of parking lots that currently cover the site. This block is the heart of Wrigleyville - the Triangle Building could be a nice jewel to complement the baseball cathedral next door.