Is it permissible to pay off debts and help those who wish to marry with money from usurious interest? And is it permissible to cover a deficit resulting from accounting system errors in a pharmacy with money from usurious interest?

It is not permissible to deposit money in an interest-based (riba) bank, even without interest, due to the assistance it provides in sin. An exception to this is made in cases of necessity to preserve money when no Islamic bank is available. In such a case, it must be deposited in a current account to minimize the harm, and any accrued interest must be disposed of by spending it on general public welfare for Muslims or giving it to the poor and needy. If a person has deposited their money in an interest-based bank out of necessity, there is no sin upon them. Otherwise, they must repent and dispose of the interest. It is permissible to pay the debt of someone unable to repay it from that interest. As for spending the interest to help someone who wishes to marry, it is not permissible unless that person is poor. Similarly, it is not permissible to use it to cover a deficit, because that is a debt owed by the owner of the money, and they are not allowed to benefit from the interest unless they are poor and in need.