if someone is shooting at car, how does the car react?
As long as it's driveable, it should keep on driving - precisely the opposite of what most people would do. So yeah, I'd go with autonomous any day in such a situation - I can duck and cover and don't have to pay attention to the road.
what does it do at four-way stop if it was the second car there but the human in the first car is waving it on?
I hate these people, just so you know.
has it been tested on drivethru fastfood?
Has your laptop been tested to work under water? I mean, shit, I like to sit and read in the bathtub, it'd be nice if I could, well, rest it on my lap, with the bottom half submerged you know. If I'm not coming across clear: the goal of a test program isn't to send people to the moon on a first launch.
does it get up to speed on onramps or does it merge into highway traffic going 45mph?
Now you're anthropomorphizing and it sounds really silly.