I wouldn't give a dog to someone who was going to use it for any of those things unless they neutered it... bite work included. There is something else besides selection that changes the direction of a family and that's environmental impact. Gene regulation plays a big role in what is being expressed and aids the changes we see in something like apbt>amstaff. While it's easy to say that the amstaff took a turn because they had no idea if they were selecting the best or worst pup of each litter... eventually from not looking at them there would be no best in the litter. Like the term "use it or lose it". I think the same could be said about bite work. Enticing the animal to bite people will naturally make for a more HA dog inheritedly just from actively participating in it. Not really something I would want with my dogs. But if others like it, go about it. Bad news for our already bad news dogs.