You could use the search function, or you could click
here. I learned a lot from reading that thread, hopefully you will too. It pretty much answer all your DI related questions. Also, once you make the uthrow->uair ineffective, the Fox will have to adapt in order to get a kill off. From what I've seen, uthrow->uair is such integral part of Fox's game it's hard for some people to be creative and come up with something new.
On a side note: Watch out for falling uairs! Those are sexy, but hurt like crazy becasue they happen really quickly. Falling uairs tend to kill me more than uthrow->uair or uair juggling does.