Must one travel with one's family to Lebanon despite the prevalence of corruption and mixing, and is it permissible to remove one's hijab in front of her maternal grandfather's adult grandson, toward whom she harbors a suspicious feeling?

If it is possible to combine travel with one's parents and avoiding forbidden acts, that is better. But if traveling will lead to forbidden acts, and staying with the grandfather protects from religious transgressions, then staying is more preferable, and there is no disobedience in that, because obedience is only in what is right. As for removing the hijab (definition) in front of mahrams like uncles, it is permissible, but if there is a fear of temptation, it is not permissible to remove it in front of him or to be alone with him.