Let your insurance company handle it. They do it all the time.
The person who is backing out
the car backing up
Any time there's a claim which will be paid by the Insurance co, a deductible is paid by the insured.
The car in motion is ALWAYS at fault when it hits a stationary vehicle.
Of course it is your fault. The fact that the car was illegally parked is of no consequence. You didn't look where you were backing or you would not have hit the parked car. Would you have hit this car if you had been looking? Perhaps the illegally parked car is a Mini Cooper, parked illegally 1 foot behind a Hummer and therefore not visable when the driver looks before backing up...
If you reverse your car and then collide with a parked car , the person who did the reversing is at fault.
The driver of the backing vehicle. The fact that the car was parked illegally is irrelevant. The onus is always on the driver of a moving vehicle to ensure the way is clear before backing up.
The one backing out, because you should realize someone is opening a door.
Several things can happen. Allowing you parked legally other than insurance: the person who hit your parked car is responsible to pay damage. If you were parked on private property the lack of insurance means nothing. If you were parked on a public road or public parking lot you could be on the hook for a ticket for uninsured vehicle, but the other guy should pay anyway. Don't admit to driving with out insurance!
If someone hits a parked car then they are automatically liable.
Yes. Being illegally parked does not affect fault. If you strike a parked vehicle, it is ALWAYS your fault because you have a duty to ensure the way was clear before moving.