OPS-center is not a discussion board, thats being handled nicely by regional and national d-boards. Its also not going to be used to enforce age related social controls other than within an event. The ASC age verification system is unique to us in Canada and is pretty contraversial when the rest of the world looks at it. I would keep it within ASC.
It doesn't use a calendar per se, what it does use is a geo-filter based on your home pin. Events, members, fields and vendors are presented geographically, not through a temporal view. I'm not against the idea, it just only occured to me how to integrate that. We're pretty much frozen on features at 1.0 right now and just debugging it for release and wider use. I can see 1.5 having some sort of temporal view.
Its also not just about what is being held on a particular day or weekend, but about where as well.
Facebook login is just one option, you can do a separate login. Its more for convenience.
Hosts aren't necessarily communicating with one another because they don't want to, it that there are a lot more games happening outside of social circles - hosts are not one entity anymore but many people. Some don't want/care to interact or coordinate with others. Many have their own boards and social circles that don't overlap with ASC. Many have firewalled themselves on purpose.
OPS-Center is a hosting and player tool, but socializing games through moderated discussion boards is still the primary way people socialize a game.