Treating one's wives with respect and consideration

Q: My parents are married alhamdulillah and my dad did a second marriage. It's been 2 years. He wants to keep both of his wives together in one home but my mother feels hurt seeing the other woman again and again. What is the rule for these circumstances in Islam? My father says my mum hurts him by asking to stay separately, he says he won't forgive her so in akhirat will there be any harm to my mum? What is her duty and her rights if she doesn't want to stay together with another woman?

Inheritance question

Q: I got confused by a Christian missionary about the so-called mathematical mistakes in inheritance explained in Quran. Since I am not an aalim, I need your help to clarify this confusion. I have firm faith that there is no such mistake in the Quran; it's my fault not to have complete knowledge about it. One example he gave is stated below:

Wife 1/8 = 3/24

Daughters 2/3 = 16/24

Father 1/6 = 4/24

Mother 1/6 = 4/24

Total = 27/24

Please help me out in this matter.

Working in the financial division of banks, etc.

Q:

1. Is it permissible to work as a financial manager or internal auditor at a conventional bank (like Absa, FNB, Standard Bank) or in the financial services division of a company whose main income is not derived from their banking division?

2. Is it permissible to work at investment banks like Rand Merchant Bank, Sanlam, Allan Gray, Investec, Old Mutual, etc.?

3. Is it permissible to work at insurance companies like Discovery, Outsurance, etc.?

Marital problems

Q: I have been married for 13 years and have five kids. When we have an argument or misunderstanding, my husband upon getting cross would say swear me and call me harsh ugly names and when I say i'm going to leave him then he says where am I going to stay? Then I would say he must move so that kids lives would not be disrupted. (We stay in an out building by his parents. Both of us are responsible for the building of this house) then he tells me iI must move because this is his house. Then he would swear me out again and again. When I said I would take the kids with me as I am always here for my kids. Then he threatens me by saying he would kill me. A week later he plays amnesia and says he is so wrong. But after a few days then he doesn't think he is wrong anymore. I have been for a fasakh but because the Maulanas knows him, they don't want to phone him. This is recurring situations and I always get sworn at. I am so tired of this behaviour. Now when I say I am tired of this and I want to leave then he wants to ban me from teaching (Quraan) or having a phone or even driving. Please help me as I am tired of his lies. Everytime he wants to make up he says I have no grounds for fasakh. Please help. Also I would like to add that teaching hifth is my passion and I would not like to leave it. Since I have been teaching, my daughter who is in my class is finishing in a weeks time Inshallah.