Regarding the baseball. Usually, if the miscreant that threw it then ran away can't be identified, you just eat the cost of the window. That happens rarely enough that I'm still in favor of kids playing ball in the neighborhood.
If heavy drones are crashing down often enough to cause problems (let's say more than a couple dozen times a year in the US), then rules will need to be put in place to curb that, sure.
I think you and I are arguing from different scopes here. My whole premise has been regarding Amazon-owned (or other commercially-owned) drones operating in our skies. You're--rightly--concerned about that guy down the street picking up a 30 lb. machine for fun, and not being responsible with it once it causes damage or injury. I think we can agree in that regulations on the craft and on the operator would apply before it's allowed to fly. Maybe the operator should be bonded and insured, and should have passed some sort of certification. The aircraft itself should meet some minimum standards of safety and redundancy. OR, if the aircraft meets some higher standard of safety and redundancy, then any civilian can operate it because it self-enforces flight safety rules.
Those same rules should also apply to any commercially-operated drones of course, but I've been assuming that, e.g. Amazon, would do this out of self-interest. They don't want to deploy a fleet of drones only to have a massive PR nightmare when things go south.
And after all these rules are in place, in the instances where someone does violate the law and flies illegally, existing insurance and law enforcement schemes would be able to handle it.
All I'm afraid of is cutting off innovation before it can occur, due to an over-abundance of caution. That's all.