I am a doctor, and sometimes I refer patients to the hospital for surgical interventions, and they give me a commission from the fees of the surgeries, even though I do not perform these surgeries. What is the ruling?
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.
If this commission is charged to the patient as part of the operation costs, then it is not permissible. Additionally, a doctor should only recommend surgery if there is a genuine medical need, and the hospital should only perform an operation when necessary. And Allah The Almighty Knows Best.
What should a person who doubted having missed a pillar of prayer do?
All praise be to Allah, The Lord of The Worlds. The prayer of one who doubts having missed one of its pillars is valid, and nothing is due on him/her since having a doubt after offering the act of worship doesn`t undermine its validity. And Allah Knows Best.
Is it true that if a ritually impure, or a menstruating woman visits one who is in confinement, harm will be inflicted on the latter, or her baby?
This is completely wrong and unfounded piece of information.
What is the ruling on someone who perform their prayer after finishing it because they believe they missed a Rak'a, a prostration, or that they did not perform it correctly (thinking their prayer was invalid)?
If he was sure that his prayer is void then reperforming it is an obligation along with figuring out the reason of invalidity so long as this wasn't out of uncertainty. And Allah Knows Best.