Dear Robert, I think that you make a valid point.  That said, it will take many more drops of water to soften, and finally remove, the stone called Vatican.  The Pope could, as Bishop of Rome, move to St. John Lateran, and lead the Church from there, forsaking all the trappings of being a head of state.  It would also be required to faithfully apply the principle of subsidiarity to the governance of the church.  It would mean, effectively, the decentralization of the church, with the Bishop of Rome "presiding in charity" (Ignatius of Antioch).  Having said that, I still think the Pope can, and at times such as the current one must, play a vital geopolitical role in addition to his spiritual one.  The instrument of wise and consistent papal diplomacy is not to be underestimated.  That is better achieved within the structure of being head of state.  But this is not written in stone forever.