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.
I have a brother who is harsh in his dealings [with me], and many problems have occurred between us, and I do not intend to reconcile with him. What is the ruling of Islamic Law on that?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is not permissible for a Muslim to abandon or boycott his fellow Muslim brother for more than three days. This is based on the saying of the Messenger of Allah, peace and blessings be upon him: "It is not lawful for a Muslim to forsake his brother for more than three [days], meeting each other but one turns away and the other turns away, and the better of the two is the one who initiates the greeting (salam)." (Reported by al-Bukhari.)
A Muslim must strive to end such estrangement (hajr), so as not to fall under the prohibition mentioned in the hadith. If he takes the initiative to reconcile but the other party does not respond, then there is no sin upon him. We remind [ourselves] of the saying of Allah, the Exalted: "And let them pardon and overlook. Do you not wish that Allah should forgive you? And Allah is Forgiving and Merciful." (An-Nur/22). And Allah, the Exalted, knows best.
Is it permissible for the guardian to give Sadaqa (voluntary charity) from the money of the orphans?
It is impermissible for the guardian to donate from the money of the orphans because he is entrusted with the safekeeping of that money, and is prohibited from donating it.
What is the ruling on applying perfume while fasting?
Applying perfume does not break the fast. However, it is better to avoid it, as fasting is a practice of simplicity and restraint, while perfume is a form of luxury.