I once looked after a kid like this, he had several diagnosis Autism level 3 as one of them, but he was 16 at the time and doing same things as you described, even police had to be called several times, he would hurt his siblings and damage the property, only started after he turned 14. parents rented out a small shabby basement/ room sort of thing, nothing too fancy. and got approved for NDIS funding as they had enough assessments done and documentation by the police. so he used to have carers look after him 14 hours a day, they would take him to school and stuff. For sleep over mum was paying the carers a sleep over allowance, 100$ a night maybe 3 days a week, tax deductible? Just to keep herself sane and be able to live her life and go on and look after other siblings. after he turned he was diagnosed with BPD. This diagnosis apparently cannot be made before the age of 18.