Is it permissible for me to complain about him to someone of higher rank? And would I be sinful if he were harmed in his work or expelled? And is it permissible to complain about him secretly for fear that he might harm me?

Denouncing evil is obligatory. Since advising the person in question did not work, it is permissible to complain about him to someone who can deter him from his actions, even if it leads to his dismissal from work and his harm. There is no sin upon you in that; rather, it becomes obligatory to do so if it is the determined means to prevent the evil. There is no harm in complaining discreetly.