What is the ruling of Islamic law regarding money that was taken, and must it be returned, especially concerning the house, charities, gifts, and money that the questioner no longer possesses, knowing that the questioner was unaware that the source of the money was fraudulent?

The fundamental principle in Mudarabah (profit-sharing partnership) is the division of profit as agreed upon. If it becomes clear that the money you received is part of funds unlawfully seized by a swindler, then you are not entitled to anything from it. If he performed a minor service with your money, then you are entitled to your share of the apparent profit, and you must return any excess to its rightful owners. Your lack of knowledge absolves you of sin, but guaranteeing the funds is obligatory upon you. If you are unable to pay now, then pay what you can, and the remainder is a debt upon you. You are obligated to guarantee the funds you received, but you are not obligated to return the house itself. If you guarantee these funds, then you will be rewarded for the charities and gifts.