As always, a most excellent post, Johanna.

Castration is drastic but I could certainly see the minute chance of eunuchs returning to the church before priests and nuns were allowed to marry, certainly those in the higher ranking positions of authority. I highly doubt the Vatican would be swayed on that one. I believe they take this belief from a rather literal interpretation from the book of Matthew, although being atheist, I do not know it to quote it.

But, as to whatever solves the issue addressed in the OP, the floor remains open. I think the only thing that can be agreed on thus far is a more rapid and fitting course of action for those caught.