What else is important to a preaching calendar/plotter?
Integration with the Daily Office or Lectionary that one uses.
What ideas using current functionality would work?
A couple of years ago I proposed that sermons, and sermon outline resources are best constructed as two resource: Dictionary and Comemntary, with cross-references to each other.
The sermon, or sermon outline goes in the commentary under the scripture it is about.
The dictionary lists sermon topics, liturgical days, etc, and the Scripture the that sermon references.
Obviously, some sermons may not have an appropriate scripture reference. They can be included in the dictionary resource. Or maybe in an external Reference Library resource.
jonathon