Is it correct that everything dry is pure even if it has impurity on it?
If something impure becomes dry, it remains impure and is not purified by drying. However, the impurity does not transfer by touching it if the one touching it is also dry. And Allah the Almighty knows best.
Is it permissible for a husband to stop his wife from visiting her family?
A husband shouldn`t stop his wife from visiting her family, and it is disliked for him to do so because such an act makes them harbor feelings of hatred against him.
What is the ruling on giving Zakah (obligatory charity) to one`s relatives?
It is impermissible to pay Zakah to one`s origins (parents and grandparents) because providing for them is an obligation on their branches (sons and daughters) if they were poor, but it is permissible to give some of the Zakah money to relatives whose provision isn`t due on the giver of the Zakah.
Is the one offering the sacrifice liable if its meat spoils?
Praise be to Allah, and prayers and peace be upon our Master the Messenger of Allah.
If the meat (of the sacrifice) spoils due to the negligence of the one offering the sacrifice in preserving it, or due to improper storage, then he is liable to compensate for the portion due to the poor (which is estimated as half a kilogram of meat). If the sacrifice was a vowed (mandatory) one, then he is liable for all of it.
However, if he was not negligent, then there is no liability upon him, because its ruling is the ruling of a trust (like an item left in someone's care). And Allah Almighty knows best.