To be charged you need another component. Recklessness behavior. If you kill someone without intent, and were not being reckless you will not be charged.
I don't think it should be a life long sentence, but definitely some kind of reprimand
You will not be charged if you did not do it recklessly. If you were not reckless you will not be charged.
Manslaughter is almost always a product of irresponsible actions. It should be condemned to discourage this.
Its involuntary. Shouldn't this be obvious?
In case of a true accident, no. However, what is called involuntary in court includes negligence, which should be.