6. Name change is compulsory if he wish to convert in to Muslim ?
Islam never insist for name change. If he wish to change his name , he can change. If he want to convert without name change, he can convert into Islam without name change. He can convert his religion alone.
9. Same day marriage will be valid if they dispute themarriage in court ? Because the girl parents are very influenced and they will
take extreme steps to invalidate the marriage ?
Nothing to worry If you complete the register marriage properly with guidance of court marriage lawyer and if you got valid marriage certificate. If both bride and groom is very clear in their stand , nobody can interfere with their own personal matter.