Did the wife err by informing her husband's father about their financial problems and his shortcomings concerning his household, and is the husband justified in becoming angry with her and leaving the marital bed because of that?

If the husband is remiss in providing the obligatory maintenance, and her complaint to his father came after she had advised him and he did not improve his conduct, then there is no harm in that. As for punishing the wife with abandonment merely for complaining to his father about his shortcomings, this is a sign of poor marital conduct. It is not permissible to abandon a woman except for 'nushuz' (disobedience/rebellion), based on the Almighty's saying: "And live with them in kindness."