His rank was Archpriest (monsignor, should we translate). As for keeping his body intact - he must have ended up with a serious burn. In his religious practice he routinely made use of corporal punishment as proper means of penance. And he actually considered that weakness to be a failing in himself, and repented it bitterly...
But again, mortification of the flesh is not a way to flee the temptation, but rather to defeat it. Mild forms of that are even encouraged, such as fasting. In contrast to any of that, castration offers no redemptive suffering.