It is a very pure soap opera, with too many open character-driven storylines at any given time, that exist mainly to ensure side characters like Tara, Sam, Jason, Lafayette et al. continue to get screen minutes.
If I was running it I'd trim the focus and try to make the central characters behave consistently in relation to their circumstances. I'd also stop adding new setting elements, new supernatural creatures etc. Each time they add a new magical beastie the initially strong southern Gothic atmosphere is diluted somewhat. Of course, you've got the source material to blame for that.
I think both Bill and Eric lost a great deal of their plausibility in season three, seeming to play against their previously established types. Eric at least had the revenge plotline to explain a lot of his activity.
