Hello,
1) The High Court can decide only the case that is before it and not the cases files in other courts.The case before the family court will have to be decided by the same court.Upon passing a verdict on the writ before it the HC can direct the parties to go back to the concerned Family Court to settle their case there.
2) If you wife is agreeable for divorce now without contesting, you have the option to convert the petition to a divorce by mutual consent or your wife has to withdraw the petition before the family court and you have to jointly file a petition for Divorce by mutual consent.
3) As regards the Dv case it must be before the court of a Magistrate. Your wife has to move a petition to withdraw the petition if your disputes have been settled.
4) High Court does not act as one stop solution and will not interfere unnecessarily in the working of the lower courts or in the matter pending before them.