Hi WoW
Please do not follow this advice w/o speaking to someone. I do not know your situation and am not a trained therapist or a poseik. I am just offering something to think about and maybe discuss with someone experienced before taking the drastic step of asking a child to leave. I also don’t know the legal or practical options with a minor. What I meant was if you really think the other children are in danger of following and the behavior is so destructive that it is causing serious damage to shalom bayit then I think you can make very clear last resort rules and expect them to be followed. I think that is showing respect to your son by giving him the responsibility for his actions. In any case laying down these rules must not be done in anger or haphazardly but with seriousness and couched in all the love you can muster.
I am glad you are finding some Chizuk here. We are all with you and hope for the very best for you and your family. Please now take the next step and find someone trained in these issues to help you get through it.