1.Since your tradition permits and recognises this marriage between the said relationship, it cannot be legally void, hence you may have to file a divorce case only, especially at this stage only a divorce case is maintainable.
2. If you apprehend such an incident, you may file a NC before the local police, clearly explaining your apprehensions, which may to some extent protect you from severe legal actions, if something happens as apprehended.
3. For child custody yo have to file a petition seeking child custody before the competent court.
4. Since it is a continuous offence, it is maintainable.
5. The biological father is the natural guardian of the child right from its birth and not from the age of 5 years. You have mistaken custody to natural guardian.
6. If she is refusing medicines, then she may be referred to any marriage counselor.
7. Yes, you can do that.
8. You can decide judiciously.
9. You can give POA deed to somebody to represent you in your absence and conduct the case in the court.