I hope to be at Isle of Palms this weekend. As I recall from previous visits (2 years ago), the Hagood site is not particularly strong at IOP. And not much is carried on the Awendaw site. SCHP and that's about it. I guess I'd be surprised if I can hear much Berkeley Co. traffic from there. But I'll let you know after this weekend.
As far as I know, all of the data in the database is accurate.
You're right about too many systems - 3 or 4 Palmetto 800 sites, Charleston Co. 2 systems, Charleston City, Military, SC Ports has an EDACS system, it's a lot for one configuration.