Let me address this from a different angle. The Kafra corporation exists to make a profit off those of us who use their services. Currently, there are only four castles. This means that the Kafras can only profit from four guilds at any given time. However, if there were rental cottages as proposed here, they could be guild-restrictive, like the castles between woe. Given that circumstance, what reason would Kafra Corp have to not expand their business? It only stands to benefit them.
It seems that Argos' intended game balance is to make pvm subservient to pvp. I would like to see them independent of each other.
Kroggles ensures the living stay living, and the dead stay dead.
Clobberella beats you up.
Teela Brown has a birdie!
Flosshilde communes with the very souls of the damned.
Walsung is actually pretty cool. For a guy made of metal.