Since FC has said that it will be possible to build towers in lower level zones, I think it's a safe assumption that one can build in zones that are otherwise non-PvP. If this is the case, attacking towers probably works differently than just attacking another player in terms of the PvP rules. So odds are neuts will be able to attack and defend normally, they won't necessarily have to follow the same rules attacking towers that they have to when attacking players in a political zone.