Yeah thanks good point about the bushings.
There seems to be two things going on here, both vibration in the steering/pulsation in the pedal when lightly braking above 60 mph and also vibration when not braking in the 70-80 mph range.
I guess the thrust arms could be bad but if that was the problem then why would the vibration when braking go away temporarily for a few months when I replaced the brakes and/or resurfaced the rotors? Do bad control arms cause rotors to wear unevenly?
The front thrust arm bushings were already replaced once around the same time I replaced the brakes the first time, but I suppose they could be bad again.