This is normal puppy behavior-some are worse than others. Replacing the arm with a Nylabone, or a chew to that he can not swallow any parts of,(NO rawhides) a good idea.You could try a spray bottle of water,it works with some-and always say "no bite" with any method. A can with rocks in it,that makes noise, is also another method,used to distract them from biting. If he has something in his mouth, and you pull at it,to him it's a game, and he will pull back. If he has a grip on something that he shouldn't, you could try having a small treat to give him if he lets go,when you say "no bite"then give him something he can bite on! I know it is very hard when you have young children and a pup,and EBD pups are worse than most other pups,when it comes to biting. It will take a lot of patience,and being persistant to get through this, but it will all be worth it. Until he learns,and has lost his baby teeth, do not let anyone play tug of war with him,because that would encourage him to bite more. Hang in there-we have all been through this,and it does get frustrating at times. My pups were obsessed with my shoes while I walked,so I got a pair of tennies on sale,and gave the pair to the pups! This,too, shall pass(but not for awhile!)
I have never used their crate as punishment,as I did not want them to hate it. They sleep in their crate at night. I had a small pen(it folds up) that I put them in when I needed a break. Sometimes when they get tired,they get wound up,like kids do.