I have a 13 and 15 Yr old who get the hump when they're told to do something, one with ASD and they have never had the kind of reaction you describe. I get sick of my own nagging sometimes but would i be deemed abusive, no way. You're unfairly getting it in the neck for the actions of a teen. And those saying he is a child, yes agreed, but my 6ft, well built 15 yr old who towers over me, knows the difference between right and wrong. Is he emotionally developed enough to run a household or make a major loge decision, no. However, he knows about unacceptable behaviour - sexual, violence, theft, etc and needs to know that unacceptable actions have consequences.
As mentioned one of my boys is adopted and what he went through up until the age of 18 months is what you call neglectful! I've fostered siblings who came from terribly sad environments and had understandable challenging behaviour. My mums friend has some truly heartbreaking stories and her and her lovely late husband fostered heavily abused kids when she retired.
Nothing you've said has indicated anything close to any of that. Assuming it is a personality disorder, what exactly do the social workers expect you to do? I have my opinions on how they tend to be unsuccessfully treated, but as its from a neuroscientific aspect rather than a clinical psychology aspect I can't say I'm well placed to publicly comment on that.
Although there are many issues with the youth justice system, there are minors within it who are learning the consequences of their actions, many who come from genuinely abusive environments. The way they're trying to push you to take your son back at the expense of the others, is in no way showing him there are any negative consequences for doing exactly what he wants, and instead the younger kids would see it as being punished, that you are choosing him over them, even though they were the ones harmed. If they can't see how THAT would cause trauma for them, they really don't care about any of you, and their claims of caring about the 15 yr olds "trauma" is bullshit. They may as well be opening their mouths and letting the wind blow their tongue around. Empty words that mean nothing.