Q: How do I perform sadjah sahw?

Q:

1. I have a lot of qadha salaah and I don't know exactly how much, how should I calculate all my salaah?

2. While performing my qadha salaah, can I perform all the Fajr, then all the Zuhr, then all the Asr and so on?

Q: If we have to read a Surah 11 times. Should we read bismillah once or 11 times before the Surah?

Q: I would like to verify if the name "Zariyah" is a Muslim name and the correct meaning of the name.

Q: I am working at a retail store as a cashier. The store also sells beer and pork and other meats... I only scan the item. Is my income haram?

I also have another job offer at a pizza restaurant that sells pizzas with toppings including chicken and bacon. Which is a better job for me? 

Q: I have a question regarding if something is haram and shirk. There's this thing called subliminals and they’re essentially these affirmations that reach your subconscious to help change some things or help improve yourself. For example, get longer eyelashes or improve your memory. Is it shirk? Also, some don’t have music playing, usually rain drops or silence.

Q: My brother took a loan from me for 2-3 days by telling me that he needs the money urgently and he had sold his shop and would get money in 2-3 days and pay me. But he was lying to me. He was under heavy debt taken from many people and was not selling his shop (I don't know if he had a shop at all). He just wanted to take money from me.

Four years have passed and he has not returned a single penny. Had he told me the truth, I would have given him only a small amount of money as a loan, and not all my money from which I was making my earning. Now he is expecting to receive some money (about 25% of my loan) but he refused to pay me. The reason is that he wants to educate his daughter at a medical college and needed money for her.

My question is: If my brother gets any money, is he obliged to educate his children first or pay my loan first? He argues that his children are his responsibility. My argument is that I gave him all my money I was using to earn a living for my children.

Q: I have psoriatic arthritis. It gets worse after each pregnancy. After my 2nd child (I have 2), the bones in my feet and knees have become bad so I can only read salaah while sitting on a chair. I can't go on my knees at all as it causes excruciating pain and I can't wake up. In my case, would I be allowed to tie my tubes after a 3rd baby?

Q: What are the duties of in laws towards their son in law? Are they obliged by Islam to call and visit their son in law more often and if he is living abroad and comes after 7 months should that son in law be invited to any party etc? If a son in law takes this as an issue that why didn't they invite me home etc. what should a wife do in this case?

Q: Can you please let me know the adab and sunnah of letters? For example, letter writing and receiving letters.