Is it considered disobedience to not give a father 1000 Riyals – given that he is not in severe need and has delayed repaying a previous debt to my husband, despite his good financial standing?

You are not required to give money to your father if he is not in need of it, and this is not considered disobedience. However, it is preferable to give him what he requests if it does not cause you harm, for kindness to parents is among the greatest acts of piety.