My two cents theory at this stage, is that the family are Shandor related which provides their link to the town and also to the first film.
I don't think now that they are related to any of the OGB's.
Right there with you. It would explain the look of the house, the doomsday mentality and the knowledge of what was coming.
Also, what's the likelihood that a Ghostbuster would have a home in Oklahoma, let alone right near this particular beehive?
Ray mentioned Camp Wauconda in the first film. There's a few different interpretations of where that is, but I think the mostly likely location is the same Camp Waucounda I knew as a kid -- just northwest of Chicago in Waucounda, IL.
Of course, I'm biased. I saw the first film when it opened in Waukegan, IL and remember the crowd reacting to that line.