My BP is a 2010, I just got him a few weeks ago and they told me he was about 6 months old. I have had no problems with him at all, and he's not nippy like I've heard babies can be, but he's young enough that he's still a "little guy". I guess it depends just on how young you want.
As far as the humidity goes, I use Zoo Med Eco Earth and it works fairly well at keeping it humid. I do mist about 3 times a day only because I use heating lights on top and that tends to dry it up, but I keep one of his water dishes right under the light too. I know a lot of people are sticklers when it comes to humidity...and it is important...but remember that these snakes are naturally from Africa...how humid is it there? lol...that's why these snakes are so amazing, because they are very forgiving, and you have time for trial and error as to what humidity control works for you. Hope this helped...