as per the information provided by you, my opinion on your queries are as under:-
1. During the trail/Cross-examination of her, those documents can be proved as fake, it is the style and strategy of your Advocate.
2. there is no requirement for any documentary proof to prove cruelty, you may prove her cruelty by way of your oral evidence before the Court, so don't worry about any audio or video of proof.
3. File an application before the court for child custody along with the Visitation rights, the court has the power to pass an order in your favour regarding the visitation rights and even for full custody if you proved before the court that you are the best person for the welfare of the child. Being the father of the child, you have all rights to protect the future of the child which is for the welfare of the child.
4. No need to withdraw the case, fight the case on merit and don't afraid with the alimony, she may demand in crores but the court shall allow only as per the status and income of the parties, so no need to worry.
5. Being a father, you shall be responsible for your daughter till her marriage, and for the wife, if she is not earning and working then till her earning.
6. if the daughter is minor then your rights shall be decided by the court and after completion of 18 years, it is the choice of your daughter.
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