Theory:Doctor Who television discontinuity and plot holes/Let's Kill Hitler

This is doctor who, and production errors are also possible! He probably was too busy at the time and didnt notice.
 * Why would Adolf Hitler, the Nazi's leader, head of an organisation, that belive all things other than there own, is inferior, carry a british wembly revolver, rather than a standard German Lugar?
 * Being shot repeatedly by bullets has no apparant effect on the robot, but later, it is knocked over, by simply being punched in the head? Surely at the least the bullets would have knocked to the ground?
 * Though slightly more reaction to the bullet might have been expected, the difference in effect would be like that between a barn getting a cannonball shot through its wall and having a hurricaine blow it over. Bullets are most effective on beings with nervous systems and squishy, irreplacable organs
 * For someone who is smart enough, to quickly disable every weapon in the room, and out think River several times, it seems abit odd that the doctor did not think, that her lipstick would be a bit dodgy, expecially since this plot device has been used for over sixty years, and he already knows that River uses dodgy lipstick.
 * Would they really build robots who don't recognise there masters?
 * They were designed to kill unauthorised people. This would stop people from entering areas they weren't allowed it. Or, for killing people who have been abducted.


 * It looks like River has now become 'good' after realising she is important to the doctor. so when exactly does she kill the doctor, or is is not river who kills him?