2006 Honda Civic Vibrations

Problem 1: I have had my car for a little over 3yrs, bought it used with about 27,000 miles. When I first got it I noticed a vibration (I feel in the seat, and steering wheel) when doing around 55 mph. I took it in they said it was caused by a bald spot on my tire. When I got four brand new tires I was noticing the vibration (not as much as when doing 55 mph). The dealership has balanced and re-balanced the tires and other repairs over the last year. The vibration is still there more noticeable at 55-60 and they can't fix it.
Problem 2: I have noticed that when I am at a higher speed (around 65 or so) and when I apply the breaks my steering wheel (to me) violently shakes untill I get down below 45-50.