How can one deal with a wife who files a lawsuit for alimony, abandons the marital home, and refuses to obey her husband, who is harmed by his mother-in-law's interference? And is it permissible to marry another woman while keeping her as his wife?

If the wife insists on working and going out without her husband's permission, she is disobedient (nashiz), and the husband must be firm with her. It is wrong for the husband to leave the home, and he may marry another if he is capable of being just. It is not permissible for the wife to seek a divorce without a legitimate Islamic reason, and if she insists, he may refuse to divorce her until she redeems herself from him. It is not permissible to punish the children because of marital disputes, for they have the right to maintenance and care, and the general rule is that it is forbidden to revoke a gift. As for the wife's mother, if she interferes in their marital life, she should be advised and reminded of Allah, and it should be made clear to her that her daughter's obedience to her husband takes precedence over her obedience to her.