Well you are simply wrong. Given that I have no pain and never have had any pain in the head of my penis. But it might be more sensitive than a circumcised one.
As to God commanding - why not get the faithful to have their foreheads tattooed rather than their foreskins removed, given that all would know who were the faithful and who weren't, being that the penis is usually not seen by most others. Or of course, one can do what so many Muslims do - dressed all in black for the females and perhaps dressed all in white for the males - so as to show the differences between males and females too - for those who didn't already know.