We went through a lot of this with my oldest (adopted from foster care at age 10) son. He had all these same behaviors, but no autism diagnosis, and does have low IQ, conduct disorder, reactive attachment disorder, PTSD. He ate anything and everything, as much as he could. He didn't care at all about getting heavy or health issues. None of that made a difference to him. His aggression and violence and property destruction became so bad we did finally get him approved for a residential facility once he turned 19. Though the behaviors did not necessarily improve, he was not ever going to be able to be safe (to us or anyone else) in a home setting, so this was the best thing for him. I wish you luck. I know the frustration. You can PM me if you'd like. We did utilize locks on some cabinets, but he frequently pulled them off so caused damage in another way that way. *sigh*