All your concerns are valid, BUT, do you really think that "average human driver" makes the right decisions that much better than the potentially *random* behavior an automated car will display in all these extreme scenarios? Yes, lets say an automated car runs over a child (and saves the dog)... but do you really think the "average human drive" would do any better???
My guess, automated systems will prove to be several orders of magnitude safer overall than current human operators... there will still be accidents, but they'll be much more rare (and perhaps much more deadly, but if accident rate goes to 1% of what it is now, that would be huge---so much so that human driving may actually be banned on most streets).
Kind of like "most car accidents involving trucks" are *not* caused by the truck driver mistake... the future automated car accidents will probably not be caused by computer error, but by someone being stupid around one.
Imagine everyone staying in lane, maintaining speed, distance, etc. And actually driving the posted speed limit on city streets (even automation wouldn't have much problem slowing down from 25mph for a child (or dog, or tumbleweed) on the road).