Online Storage / Singleplayer:
this could be offered for free or bought, it would allow the haven and hearth player to go into an online storage and effectively 'bank' there valuables, (i would suggest online land due to modding offline storage) this coyuld also offer a single player version of the game, for those who do not like the risk of being griefed, as such, a offline 'private' server tool could be released allowing players to create new servers with new players, which would stop risks of strangers griefing and stealing.
Brief:
offline private / online private
free /upgrade / monthly
maybe bought in game? or maybe a certain room that only the builder can go into?
Oath Of Peace:
One more thing: I call it the 'Oath Of Peace', this allows the player to swear his haven and hearth character to a life of not stealing/murdering, this would also stop him from being murdered of griefed by other players, this oath could not be revoked later though
Dirt In Stone:
This is quite simple if there is a square of 'plowed' land with a ring of stone/gold etc. tile around it, grass would not recover on those 'plowed' patches
This would be slightly more realistic as grass doesnt fly.
Good extension for people annoyed at having to plow single squares when farming.