Just put the guy in a solitary jail cell for the rest of his life, plenty of hard labor. Nothing extreme though, wouldn't accomplish anything. It's not going to help the little girl if we do nasty things to her abuser.
No, I don't like your idea. I think I would remove his vocal chords, so he couldn't communicate. I may also blind him. I'd definitely castrate him and I can't decide whether to put him in a cell block with hardened murderers or to leave him in a dark, wet cell for the rest of his life.
Yeah, that would accomplish so much. The little girl is really helped by your plan. I also would provide free, tax-payer funded, care/treatment for the little girl to help her get over it.
Which is more important to you in this case, helping the girl or punishing her father?