My brothers refused to wear deopderant or brush thier teeth until they got interested in girls. Then oh man, they were squeeky clean and wearing Stetson! So, I understand a preteen boys' smell. I also understand how embarassing it is to have your way of life questioned and judged. But the bottom line is, as you stated, your sons place of residence is on the line. So, whether you think it's fair or whether or not you agree doesn't really matter. Even though you can justify all this to yourself and the people in your life, it's progressed passed that point.
Now is the time for action. You're a mama bear trying to protect your baby cub. Take no prisoners mama. You have to give the cats away. Cat vs kid - kid wins every time. You have to get rid of the stuff. Have a garage sale and sell enough stuff to buy a storage shed. You may have a clutter problem or you may have a hoarding problem. If that's the case, ask for help. If the court or CPS see that you are taking steps to correct the situation or that you are asking for help, they will work with you. Contact the school counselor and ask if there are any family counsleing resources for you and your son. If he is acting out and you know that, it will be your responsibility to try and get him some help for it.
I know it's easier said than done. But if the house were on fire, you would let all that stuff go to save him. Well mama, your house is on fire! Do what you know you have to do. Love and strength to you and your boy.