What is permissible for the husband to do as far as having sex with his wife is concerned?
The couple are free to enjoy each other sexually provided that they don`t do it during menses. It is also forbidden for the husband to enjoy the wife from her anus.
How are those killed in wars punished with the torment of the grave if they are not buried?
The torment of the grave refers to the suffering that the deceased experiences between the day of their death and the Day of Resurrection, which is called the Barzakh period. Similarly, it includes the blessings of the grave, whether the deceased is buried or not. And Allah The Almighty Knows Best
Is love allowed or forbidden in Islam?
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
If love refers to the involuntary inclination of the heart, a person isn`t held accountable for it; however, whatever follows this in terms of gazing, meeting, and the like is forbidden. And Allah The Almighty Knows Best.
Is it permissible for the big brother to force his sisters to wear Hijjab (Islamic wear) if their father didn`t do his part in this regard ?
All Perfect Praise is due to Allah, The Lord of The Worlds
The father`s attention should be drawn gently and politely, and the sisters should also be reminded with good words since Allah, The Almighty, Says (What means): "O ye who believe! Save yourselves and your families from a Fire whose fuel is Men and Stones." [Al-Tahreem/6]. And Allah Knows Best.