pro3racer.. That would be 56 fronts and 55 rears. If you were to try 50 all the way around I would swap the pistons front and rear. As for the front arms, that bar is there for durability reasons. If its not there the arm will much easier to break.
Magic.. All you need is a good pair of scissors.. you want to try and cut as much of the teeth of without damaging the actual belt. On mine all it did was basically flatten every other tooth so they do not touch the pulley's.