Is it better to convert the association's account from a non-interest-bearing current account to an interest-bearing account, so that the interest can be used for general Muslim affairs, or to keep it as a non-interest-bearing current account, knowing that the bank benefits from the money in both cases?

If it is permissible to open an account in an interest-based bank due to a recognized need, then it must be a current account free from interest. As for opening an account with interest, that is precisely usury and incurs curses. The intention to use the usurious interest for good deeds does not remove the prohibition.