The shock eyelet differences between 1979-86 and 1987-93 are due to the 7.5" differentials not using lower shock mounts. The 8.8" differentials use a shock mount, so the eyelet and bushing size are different.

There is absolutely no need for quad shocks on a Mustang that has a TA installed. The quad shocks are oriented so that they move the most when the axle housing is rotating (during wheel hop). With the TA, there is very little axle housing rotation, because all of the rotational compliance in this direction has been removed.

You still need the vertical shocks in the rear suspension with the TA.

The difference between a strut and a shock is that the strut is also a suspension pickup point. It defines the motion of the wheel during suspension and steering motions. Remove the strut from the car, what happens? Suddenly the car has 45 degrees of camber. Remove a shock from the car, what happens? Nothing.