Various masaail of Nikaah

Q: What status does nikaah hold in Islam?

Q: Question is it my cousin he is missing from 10 year 7year to go he did not contact with wife according to one has kno wn person in Australis he say i will never contact with my family but problem is it has wife wanted to merry with me because she have 2 kids and very Alon and she much love me what we can do?

Q: Is it permissible for women to remain alone in their homes in order to allow their husbands to go out in the path of Allah (jamaat) or on business trips, etc. Please explain the correct Shar'iee ruling?