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
What is the ruling on someone who perform their prayer after finishing it because they believe they missed a Rak'a, a prostration, or that they did not perform it correctly (thinking their prayer was invalid)?
If he was sure that his prayer is void then reperforming it is an obligation along with figuring out the reason of invalidity so long as this wasn't out of uncertainty. And Allah Knows Best.
Is vomit among the nullifiers of Wudu (ablution)?
Vomit does not nullify Wudu, but it is a Najaasah (impurity) that requires rinsing the mouth and washing whatever became dirty by it since the prayer becomes valid only after the removal of Najaasah. And Allah Knows Best.
If the fasting of nine years has accumulated upon me, I wish to make them up by dividing them over several years, as it is difficult to fast them all in one year due to their large number. Consequently, expiation will be due on me. Is it permissible to pay the expiation after completing all the make-up fasts, even if it takes years?
If the fasting was broken due to a valid legal excuse, it is permissible to divide the make-up fasts over several years based on one’s ability. However, if a person passes away before completing the make-up fasts, the heirs must fast on their behalf or feed one needy person for each missed day.
If the fasting was broken without a valid excuse, one must hasten to make it up. Should the person die before completing the make-up fasts, the heirs must either fast or feed the needy on their behalf. As for the expiation, it is calculated after completing all the make-up fasts. And Allah Knows Best.