They have been replaced with a set of EBC GD rotors and Hawk HPS pads :

 

Grease will draw brake dust and road grime and really gum things up.

 

The pad started wearing at a slight angle due to getting caught in the groove that the pad sits in. The notches that the pads sit in on the bracket should be lightly sanded and cleaned. Lightly lubricated so the pads will not twist any when there is no force from the caliper. Those little wire springs on the pads help push the pads off the rotors when released. The pads are catching in the corners of the groove from rust build up and not fully releasing the entire pad surface. Just clean and lube the notches if you notice rust starting to build up again.

 

You may be right because the HPS Pads were a lot easier to install than the Ford ones.

 

Did you find the root cause of your problem? Almost looks as if you are developing the same bad wear pattern on your new rotors? At that point the only thing left is a faulty/failed caliper, more specifically one or both of the pistons are cockeyed/piston boot/seals could be folded on one side from pushing the pistons back in too fast or with uneven pressure.

You could also use an IR temp gun to make sure both front rotors are running about the same temp, ect. If a caliper is indeed still dragging it should show a significantly higher temp than a free running one.