For those whose pedals pulse just as they're coming to a stop, that can be caused by a number of things. In general, the ABS cycles because the sensors are telling the system that a wheel has locked prematurely. The system is doing what it thinks it needs to to prevent a skid. However, in your cases, the wheels are not actually locking, the system just thinks they are. That can be caused by a bad sensor, wiring issue, or bad control module (air bubbles in the lines will not cause the ABS to activate).
The only way to really know what's triggering it is to have a technician connect an ABS diagnostic scanner (or NGS or WDS scanner) and watch the ABS sensor inputs to the module. They'll be able to see which of the sensor(s) is triggering the ABS event.
Now, if it was my vehicle, I'd check three things:
First, I'd do a visual inspection of the usual suspects: Check the wiring around the ABS module and pump for any signs of damage. Check the wiring at both front wheel speed sensors and the rear axle speed sensor on the rear differential. Look for any cracks in the insulation, chafing, loose harnesses dangling in the breeze, or any signs of damage to the sensors or connectors.
Second, I'd take a chance on the problem being the rear ABS sensor. It's mounted to the diff, and, on the second-gens at least, it's exposed to a lot of abuse due to its location. It's usually less than $20 and is held in by one screw. It seems to fix a lot of the ABS and 4WD issues we see on this board. It's worth a shot.
Third, I'd take it to the dealership (or an independent shop) equipped with the afore-mentioned diagnostic systems AND a knowledgeable technician that's experienced in using them. *Most* Ford dealers should be able to diagnose the issue after a short test drive. If you can regularly reproduce the conditions when it happens, that'd probably be helpful to the tech in diagnosing it. Don't tell them 'the ABS pulses when you're stopping', tell them that the 'brake pedal makes a funny vibration when you're traveling XX MPH under 2/3 to 1/2 braking force with the wheel cut to the right only' and let them do the diagnosing. Simply hooking a scanner up to it while it's sitting still won't tell them squat.
Please note that there may be a charge just to accurately diagnose the problem. In the case of Ford ABS systems, it's often-times money well-spent as it can save tons of (expensive) guessing about the problem.