Not tying down a deed to a space certainly makes it easier. Also combining building plans with deeds seems sensible, since a player would know what sort of thing they would want to buy. If I understand correctly, those deeds (like a tower deed) would only provide a base building which can then be expanded/improved using things from building shop. Another small idea - ability to name the map entrance as it will appear on the world map, like "Casper's home". This would allow players to easily find the right plot.