Oh, essbee, hugs - horrible situation to deal with. My DS2 has destructive tendencies too but hasn't been through what yours has - it seems that whenever something's not right for him he goes off and spoils something that isn't his (has scratched furniture, torn wallpaper etc).
I have in the past ripped up something of his just so he knows how it feels - he seemed to get the point but carried on doing it anyway. It's so hard to know what to do, or whether anything you say or do will make a difference. I agree with Galaxy that he needs to contribute towards replacing the trampoline - will he get any money for his birthday? Because if so that could go towards it.
Of course you love him and he does know it, but there is such a lot going on in his life - even though he is happier at home without the AH, his mind probably goes round it all, and the bullying must make him feel even worse.
Sorry, really can't help, just loads of sympathy from me. XXX