You do not need to pre-kill an ASF to feed it to a Ball Python. I have only been bitten once by an ASF in over a year of keeping and breeding them. I reach into tubs and pet the parents, even while they are nursing a litter, and never get bit. I have heard that many ASFs are mean, but have not experienced it with our breeding group as of yet. Now, I typically do not hold them like a hamster, primarily because they like to jump, and are very fast. We had three get loose in the rodent room awhile back, and chased them for over an hour to catch them. We actually degloved the tail on one female while trying to coax her out of a corner under a rack. Even after that traumatic experience, she is still fairly calm and doesn't bite as of today.
This was not to start a large debate, but to share our experience with these rodents. I definitely think they have a place any sizeable collection, but are not necessary for the average hobbyist.