Q 1: Allah (Exalted be He) has guided me to perform Hajj but after I returned,
I doubted that one of the pebbles which I had thrown did not hit the pole but it only fell inside the pool.
This is just a mere doubt. What should I do if this is true?
Doubt is overlooked and nothing is due on you. Supposing that it did not hit the pole but fell into the pool, it is sufficient because hitting the pole is not needed but it is required that you throw them and they will fall into the pool. (Part No. 11; Page No. 275) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.