His sins would likely fit in the Maimonidean category of sins that preempt repentance/forgiveness. He has untold numbers of individual victims who suffered shame and emotional distress due to his actions. He may well have been machati eth harabim (causing communal sin) by discouraging halachik mikvah use, which is one of the categories of sin for which one forfeits one's share in the world to come. This in addition to the huge hillul hashem (desecration of G-d's name) he created, which is never atoned for before death. See, e.g., Maimonides' Yad Hachazaka The Laws of Repentance 4:1 and 4:3:
עשרים וארבעה דברים מעכבין את התשובה. ארבעה מהן עוון גדול; והעושה אחד מארבעתן--אין הקדוש ברוך הוא מספיק בידו לעשות תשובה, לפי גודל חטאו. ואלו הן: (א) המחטיא את הרבים; ובכלל עוון זה, המעכב את הרבים מלעשות מצוה
Twent-four categories (of sin) prevent repentance. Four are egregious sins that if one does of these four, the Holy One, blessed be He, does not enable him to repent because of the enormity of his sin, namely: 1. one who causes the masses to sin, and included in this sin: one who prevents the masses from performing a commandment...
ג ומהן חמישה דברים העושה אותן אי אפשר לו שישוב תשובה גמורה, לפי שהן עוונות שבין אדם לחברו, ואינו יודע חברו שחטא לו, כדי שיחזיר לו או ישאל ממנו למחול לו;
And amongst them five categories (of sin) that it's impossible to fully repent for because they are sins between a man and his fellow and he doesn't know who his fellow is that he sinned against that he could... request his forgiveness...
As afar as punishments in human hands, without a Sanhedrin, in the exile today we do not mete out physical punishments, other than social ostracization. In the times of the Temple, there would also not have been a biblical punishment of lashes etc. since one could only really talk of monetary damages for shaming a fellow.
