Is it permissible for one to shake hands with his uncle`s daughter?
No, it isn`t because he is a non-Mahram (Marriageable) to her.
Is it permissible to go to the bathroom wearing a necklace that has the word "Allah" inscribed on it?
All Perfect Praie be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions.
Anything that contains words pertaining to Allah, The Almighty, is desired to be left outside when going to the bathroom, or to be hidden for fear of losing it. And Allah Knows Best.
Is it permissible for a suitor to go out with his fiancé upon the conclusion of the marriage contract?
Upon the conclusion of the marriage contract, the woman becomes lawful for her husband. However, the customary practice should be observed in this regard since rights could be lost in case of divorce, or death.
Zakah due on a woman`s jewelry?
Obligatory Zakah (obligatory charity) isn`t due on a woman`s jewelry used for adornment, provided that the value of each piece is within the range amongst common market price. And Allah Knows Best.