Who Has the Authority to Receive a Papal Resignation? Some Dangers and Difficulties in Papal Retirements

Problem #1.  One major difficulty in a Papal resignation is that a resignation is supposed to be submitted to a higher authority and accepted by that authority to be valid.  The Holy Father having supreme and absolute authority on earth has no superior authority on the earth competent to receive or approve of  his resignation.

Problem #2.  Implicit in the resignation, therefore, is a subordination of the Papal supremacy to our acceptance of the resignation.  Thus, there is an outside authority which judges the legitimacy of the reigning Pontiff.
This seems a very dangerous precedent in that we are placed in a position to determine when a Pope no longer reigns and perhaps also of establishing the criteria for ousting a Pope deemed unfit for whatever reason.

Problem #3.  The relationship between the resigned popes and succeeding popes can bring further problems of supreme authority.

Problem #4.  Full authority should also mean perpetual.  If it is not perpetual it is not full.

Problem #5.  It seems to me that we have just as much authority to reject his resignation as we have in accepting it: none!  His resignation puts us in a very perplexing situation.

Problem #6.  Papal resignations are not infallible.  It is a disciplinary matter, not a matter of faith or morals.  Pope Benedict could be making a mistake in this.

Problem #7.  What if the Cardinals gather and decide that they have not the authority to elect another Pope while this one is alive? that they have no competence in the matter.  Then we might have a stalemate.

Problem #8  The Problem of precedent.  Some claim that this is really the first time in history that a truly reigning Pontiff attempts to resign.

N.B.  Wikipedia has a decent article on the canonical and historical question of papal abdication.