Washing one's hand after cleaning the toilet

Q: I have a western style toilet and one day after urinating and defecating in it, I flushed it. However, because there was a lot of tissue in the bowl, the toilet became blocked and the bowl filled up with water after flushing. I put my arm in this water to try and unblock it. As far as I can remember, the water looked clean. One or two tissues with feces stuck on them remained in the water, however. But as I mentioned, I don't think the toilet water had its characteristics changed. Did my arm become najis when it was immersed in this water? Because I'm unsure that the characteristics of the water were changed after flushing, do I have to assume it was najis as the water was definitely filthy prior to flushing? Please put my heart at ease as I'm worried najasah has been spread.

Adopted child

Q: A child has been adopted by a South African Indian family. By what title may he address his adoptive father, mother and grandparents. Is it permissible to teach the child to say abba, ummi, dada, dadi, nana and nani? At what age is it appropriate to inform the child that he is adopted or should we adopt silence in this situation?

Purchasing a house on mortgage

Q: I have a question that I personally don't have any house or any land in any of the countries. We always hate interest and never did any business or anything else where interest is present. Our income is 100% halaal with an office job. If I buy a house with a mortgage in Canada for personal living with the niyyat of paying it off as soon as possible (within 5,7 years), is it permissible?

Reciting Qur'an for one's child

Q: When I fell pregnant with my little one, the Moulana advised my husband and I to read as much Quraan as possible to the baby in the womb. Now that he is born, I am trying to continue. While he plays, I pray Quraan aloud to him and when he sleeps I play surah Yaseen, Ar Rahmaan , Yusuf or surah Maryam from my phone. Alhamdulillah, I know reading Quraan can bring overall benefits to the baby but I was wondering if anyone knows specific benefits? Or can someone advise me on how to do this better?