I would like feedback
Before I say much, I should tell you that recently stepped away from my SSs completely, so I may not be unbiased here....
If I were you with children in my home? I wouldn't allow him to come back until he had made significant progress with a therapist. Effective immediately. That doesn't mean that your husband can't still spend time with his son, I just wouldn't allow him in your home, whether you were there or not. He's shown blatant disregard for your home and possessions. He's lost the privilege to be there.
As far as websites saying that you can look forward to arson and vandalism? He's ALREADY a vandal. The behavior he's exhibiting is so not what any good parent would want their children exposed to. Just because he's your husbands son and your kids step brother doesn't mean he's not toxic.
This kid has some serious issues. If either of his parents honestly want him to grow up to NOT be in prison, they need to step up and get that kid some SERIOUS help. Today.