Joseph:
Sorry, it is not about rishus. You know that, and are making that statement to irritate others.
philo:
It falls in the psychological realm, and it is not about being evil. You know that. When it is your kid ch”v, your eyes are more open. Sit shiva on an OTD kid? Not according to halacha. and taavah is a mental health issue. I am not applying diagnostic labels to it. Lastly, you try to pin 100% of responsibility for OTD on the kid. Have you ignored the abuse, neglect, and rejection that was inflicted on the kid? There are many people who get the respect as mechanchim etc. who will have serious din vecheshbon for the abusive impact they had on their talmidim. And I would never defend those that embarrass and shame talmidim and calling it the mitzvah of chinuch. This form of abuse ranks high among the elements that push someone OTD.
DaMoshe:
Conversion is unrelated to OTD. The person converting is doing so for ideological and intellectual reasons, and has a serious problem with belief. The OTD is escaping pain and suffering, and is involved in reacting emotionally to events and situations of his life. The many OTD kids I know have never wavered in their belief or emunoh. They are on an emotional course of escape, angry, rejected, with poor choices of how to respond to these internal and external issues. They do not progress to conversion as a next step.