Is the remaining money considered suspicious after a sum that did not belong to the questioner was stolen from him, then his friends helped him, resulting in him having more money than the stolen amount, so he repaid the one from whom it was stolen and fulfilled some of his needs with the remainder?

The actions of the friends are commendable and rewarded, if their intention was for the sake of Allah, as Allah the Almighty says: "Indeed, We do not allow to be lost the reward of whoever does good deeds." And as the Prophet, peace and blessings be upon him, said: "Whoever relieves a believer of a worldly distress, Allah will relieve him of a distress on the Day of Resurrection. And whoever eases the burden of a debtor, Allah will ease his burden in this world and the Hereafter. And Allah is aiding the servant as long as the servant is aiding his brother."

As for the donated money, reference should be made to the intention of the donors: If their intention was only to compensate for what was stolen, then the excess must be returned to its owners unless they permit its use. If the intention was to give and show solidarity without specific restriction, then you may keep what exceeds the stolen amount.