What do you advise a young man, residing in Saudi Arabia, whose fiancée is in Syria and complains a lot about his lack of communication with her, to the extent that she cursed him and then apologized, then sent him a vulgar and insulting message after he asked her mother to bring her to her senses, leading him to consider divorcing her?

One must proceed cautiously in these matters. It appears the girl is hasty and her actions towards you, such as cursing and insulting you, are not permissible in Islam. This contradicts the husband's position of guardianship. You also erred by speaking with her mother. We advise you to be patient with her and teach her matters of her religion, especially good manners, understanding the husband's status, and maintaining a good marital relationship. If her conduct improves, then proceed with completing the marriage. However, if her ill-manners are deeply ingrained, it is better to divorce her before consummation.