Is a woman sinful for seeking divorce from her husband due to the mentioned reasons of abandonment, bribery, housing a stranger in the marital home, insulting her family, and sending her alone with her children without a mahram?

Marriage is one of Allah's signs, and its objectives are tranquility, affection, mercy, chastity, and procreation. If these objectives are not met, then divorce becomes permissible. What you have mentioned—abandonment, ill-treatment, and consuming unlawful earnings—permits you to seek a divorce, based on the Prophet's (PBUH) saying: "Any woman who asks her husband for a divorce without cause, the scent of Paradise will be forbidden to her." The phrase "without cause" means without a hardship that compels her to do so.