Is a marriage contracted civilly in a foreign country considered religiously valid, given the intention to complete the contract in an Islamic country and name the dowry later, and am I sinful for concealing my living with my wife from my parents, and what is my responsibility in this dispute that led to the request for divorce?

There is no harm in documenting the marriage contract in Western courts. The conditions for marriage do not include mentioning the mahr (dowry) in the contract, but the guardian (wali) is a condition for the validity of the marriage according to the majority of scholars. If the contract is made without a guardian, it is invalid, and repentance is required, along with separation from the woman or a new valid contract. As for concealing residency, there is no sin in it. If the father of the girl delegates a man to perform the contract, the contract is valid. If he consummates the marriage with her before naming the mahr, she is entitled to a mahr of the like (mahr al-mithl). And valid seclusion (al-khalwah al-sahihah) has the ruling of consummation according to the majority of jurists.