Doubting one's imaan

Q: Ever since I was young I wasn't that close to Allah but I started sining and decided that I will repent to Allah and inshallah he will forgive me I started praying doing good deeds after exactly a month from doing tawbuh I started getting doubts it ruined my entire life until I went online and found that the companions of our prophet Mohammed sallallahu alaihi wasallam had doubts and the prophet told them that this is pure iman so I wanted to make sure if I'm on the correct path or not or Allah will punish me for doubts and what can I do to let them go.

Marital problems

Q: After 1 day of our marriage, my husband has told everyone that he doesn't liked me as it was an arranged marriage. However he saw me after engagement and was satisfied but now after marriage he says he will not live with me.he does not come home and sleeps in another room,dont even look at me and not reply my salam.I haven't told my family about me.My inlaws behave good with me and they all like me.what should i do?

Disposing of interest money from different bank accounts

Q: I have 5 bank accounts in india and all are giving interest on my deposited money. when i got interest i will write in my diary date and amount and after all banks have given interest i will add and sent all the amount to charity like patient or orphan for education etc. but this amount i will sent from one bank. my question is my method do doing interest money is correct or shall i withdraw cash from each bank separtely and pay for charity. please expplain the right method of interest payment.

Black magic

Q: I wanted to know if black spirit exists? I sometimes feel pains in my whole body like someone is doing magic on me. There is a guy I know he's my class mate but when I think of him unintentionally I feel fearful. I can't even hear his voice even I can't look at him I don't know but I think he has done some magic on me. I'll be very thankful if you help me ...

Imaamat of a non-baaligh child

Q: My query is regarding the hadeeth of the child Sahaabi who performed salaah behind Nabi Sallaallahu alaihi wasallam and then went to his tribe and led the people in salaah.

1. Can the exact hadeeth be given with the references.

2. Is it permissible to use this hadeeth as a proof for a child being allowed to do imamat (albeit for taraweeh)

3. If possible, what is the fatwa of the A'imma Arba'a with regards to the above maslah.

I only ask this as recently in a musjid, naa baaligh children were allowed by the mutawalli of the musjid to lead the taraweeh salaah.