1) We have a kid in our family who is angry almost every time. Is there a dua to calm him down?

2) We also have some family issues that has lasted for decades. One of our men in family has had absolutely no luck in getting married. Decades have gone by but everyone rejects him. What can we do? Every female rejects him either because of his age or his appearance. He has no requirements for his wife. He only wishes for a pious religious wife. What should he do?

1- This is not a dua issue. It requires good raise up ways by parents.
2- Let him take care of him self (appearance), and try to find a woman that matches with his age.
If he is not able to find a girl, let him marry a widow or a divorced woman.