Does not expelling a brother who assaults his sister from the home, due to fear of scandal, prevent the return of sustenance to the family, and is the father's dealing with a non-Islamic bank considered usury and a cause of poverty?

The questioner and their family must advise their brother and warn him of the consequences of the sins he commits, and prevent him from the causes of forbidden things. He should not be expelled from the house unless it is the only way to stop him from evil without a greater harm. As for the father's dealings with a usurious bank, it is one of the greatest abominations, and he must repent to Allah and deal with a Sharia-compliant bank or a permissible investment. When calamities strike, a person must review themselves, repent from all sins, be diligent in performing obligations, and avoid disobedience. If a person is righteous, then calamities are a test to raise their ranks, and they must be patient and certain of Allah's mercy.