I think the hub is plenty in terms of non PvP areas, I agree that it should be 100% non PvP though. Personally I'd keep Barterground merely because it already exists, and people use it, if anything I would add a bunch of NPC traders there too to give it more of a draw.
I like that most towns are dangerous to walk through personally, most of the time no one is even there anyway, the threat of dying is present but not ever present.