Yeah, there are quite a few reasons, but one is that they use a lot of those hormones to grow, for their bones and health, etc. So I'd take some time and read up on that more.
And I know, I would have to enforce a whole lot of training as soon as I get him, and expose him to as many different scenarios/areas/terrain as possible while he is still young. Don't need him chasing after every squirrel he sees right. As for finances that is truly not a concern for me as I know he will be completely taken care of, between my parents and myself, he will be more than fine.
As for walks I would hope every other person doesn't freak out and scream pitbull, but to bad if they do. I don't mind stopping and explaining, and I'll have his paperwork at home so I have nothing to worry about. But like I said, I'm a nature lover, so I'll take him to different parks, trails, forests etc. Right now I do take my Yorkie, but he can only go so far before he decides he is to tired to walk anymore - He will start by my side or like a step infant of me, and by the end of "his" walk (not mine) he will be trailing behind me. I would personally never take him to a dog park, because I have seen how careless people can get there, I've seen a good three or four big fights, thankfully was not apart of any, but I don't like that environment. Unless its off hours and there are only like two dogs or three dogs there, but if you go when its busy -easily 30-40 dogs, people start conversations with others and let there dog get away from them and yeah.. He can meet other dogs at local parks, events, and during his training sessions, hopefully make some friends and we can go out together. I found a couple places around my area that offer heated, salt water swimmer pools for dogs, so I thought that would be a nice place for him to go to from time to time. And some that have training and agility courses which is another good way to train and exercise together.
I found a couple really good trainers. But I continue to research. Just as, I've found two or three breeders I may consider, however I continue to research. Both to find more information about those I am interested in, and to find other possible breeders. I actually like driving so I don't mind going 10+ hours for the pup, on the way back I can stop hourly let him walk around and potty and what not. I see it as a better option that shoving him in a tiny crate on an airplane for x amount of hours. Cost wise it's not that much of a difference, gas vs. an airplane ticket, but I don't want to put the unnecessary stress of a flight on him. (And they put him with baggage right?...ew!) Heck I'm not a huge fan of planes myself, why should I make him deal with that.