My biggest piece of advice would be to do your aways as early as possible so you can get letters. I would advise doing two aways, at most three. Go to one place you think may be out of your reach and go to one place you think you might have a good shot of getting into.
As for doing sports/peds/subspecialty, it's a tough call. I guess the most important thing is to work with as many attending/residents as possible and get your face known. Taking call is an absolute must at most places if you want to make a good impression. So I guess if you can do sports/peds and still take call with the trauma team, you'd be OK.