Should nail polish be removed before making ablution?
Yes, it should be removed because it prevents water from reaching the nails.
What is the ruling on performing voluntary prayers during official working hours?
All perfect praise 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
There is no harm if there was break time during official working hours, but if not then it is impermissible. And Allah Knows Best.
What should a person, who doubts the validity of his Wudu, or over performs it, do?
One who doubts the validity of his/her Wudu while performing it should redo it until he/she is certain of having attained purity. But, if doubt was after having performed Wudu, then he/she should not pay attention to that as doubt after the end of an act of worship does not count. This is of course in case doubt was within the reasonable limits since once it goes beyond that, it becomes a whispering of the Shaytaan (devil) which he/she should ignore as the Wudu is valid.
What is the ruling on aborting a fetus affected by thalassemia?
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.
If this is recommended by a trustworthy doctor who is god-fearing and knowledgeable, then it is permissible to have an abortion because some types of thalassemia are dangerous while some aren`t. And Allah The Almighty Knows Best.