Is it permissible to repeat the Istikhara (seeking guidance) prayer, and is it a condition that one should sleep after offering it?
All perfect praise be to Allah,The Lord of The Worlds Istikhara is offered once, but it is permissible to repeat it, and sleeping after offering it is not a condition for its validity. And Allah Knows Best.
Is Zakah due on the orphan`s money?
Yes, Zakah is due on the money of the orphan.
Is it permissible for a woman to leave her house wearing brightly colored clothing?
Brightly colored clothing is of woman's adornments, however; and this shouldn't be revealed save to her husband and Mahrams. And Allah Knows Best.
A Christian woman wants to marry a Muslim man through an unregistered marriage contract and for a specific period because of certain circumstances. She is an adult and wants to know the correct procedure so as not to make any mistakes. What is the correct thing to do in this regard?
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Every marriage should be conducted through court in order to preserve the rights of the spouses and avoid any accusations. In fact, a person shouldn`t be ashamed of what is lawful. Rather, he/she should overcome those circumstances and start in the correct way. And Allah The Almighty Knows Best.