Do I incur any sin towards God or the deceased, despite the forgiveness of the deceased's family, my financial assistance to them, and their filing a compensation claim against the insurance company?

Blood money (Diyya) and expiation (kaffara) are not obligatory if the deceased was negligent by walking on a road not designated for pedestrians, and you were not negligent. However, if there was negligence on your part, then blood money and expiation are incumbent upon you. But since the family of the deceased has forgiven the blood money, it is waived. As for expiation, it remains obligatory upon you, and it is fasting for two consecutive months. If the family of the deceased demanded blood money and the insurance company paid it, then they have received their right. As for expiation, if you were at fault or negligent, it is incumbent upon you. But if the mistake was from the deceased and there was no negligence on your part, then nothing is incumbent upon you.