What is the ruling on reciting verses of the Holy Quran on water, then drinking it?

It is permissible to recite Quran on water, then drink it as a kind of treatment since the Quran heals. Allah, The Almighty, says:” We send down (stage by stage) in the Qur’an that which is a healing and a mercy to those who believe: to the unjust it causes nothing but loss after loss.”{Al-Isra`/82}.

What is the ruling on the mother who resorts to practitioners of witchcraft to make her son hate his wife?

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.

What she is doing is forbidden and amongst the seven destructive sins. Hence, she must make repentance, seek forgiveness from Allah, regret what she has done and adhere to the teachings of Sharia. And Allah The Almighty Knows Best..

Is it permissible for a Muslim woman to go out wearing adornment and not putting on her Hijjab (Islamic wear)?

It is impermissible for a Muslim woman to go out wearing adornment, and not having her Hijjab on.

Is it incumbent on a wife whose husband hasn`t gone to bed with her (for sexual intercourse) for many years to observe `Iddah (waiting period) upon his death?

All perfect praise be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhmmad and upon all of his family and companions.

Upon the death of the husband, a wife is obliged to observe the `Iddah even if he hadn`t slept with her because she inherits him. And Allah Knows Best.