I definitely feel that these symptoms are brake/rotor related. The ball joints could never have caused the vibration that you are referring to on braking.

If any one of the suspension components, on one side, has failed, the vehicle would pull. So, I am leaning away from any of the suspension bushings.

Have the mechanic setup a dial indicator (he ought to have one) and measure the runout of the face of both brake rotors. To do this, remove the wheel, setup the indicator on the face of the rotor, and rotate the rotor.
The runout should be about .001 or less. You will probably see numbers at .005 or above for the symptoms you are describing, if this is the culprit.

Now, if you get a high value, it does NOT mean the rotor is bad. The mounting face for the rotor might be dirty or rusted and the mechanic simply slapped a brand new rotor in place. These vehicles are very sensitive to runout in the rotors, no matter how it occurs. Such a condition can also occur if the wheel bearing is damaged (unlikely, but possible).

The aforementioned test is very inexpensive and valuable.

Consider additional suggestions from others. However, do NOT spend any more money throwing parts at it. The problem that you are experiencing can be diagnosed with the proper knowledge and measuring equipment.