I must say it sure sounds like he is bored. If there is anyway to keep the kids toys and other things out of his reach and supply him with plenty of toys of his own, he might be okay.
It is all about training, and if he thinks what he is doing is okay, he will continue to do it, and sadly to keep him tied up or in a kennel isn't going to help, because he will most likely continue to be distructive to gain the attention

Any dog that receives the proper care and training can overcome a destructive type behavior.
I have surely gone through my share of things being destroyed from all my years of foster and rescue work, but I will admit I have never fostered a dog that couldn't be trained properly and become adoptable

I have no advice for you to get your parents to let you foster him, but I do wish you all the luck.
I hope it works out for you all in the end
