I wouldn't worry about attitude problems with a BP...they are generally very chill.

As far as health problems...I would think the main concern would just be dealing with "neglect" type of problems like stuck/retained shed, or being skinny (because they only need to eat once a month according to the pet store ) or dehydrated. That describes most of the BP's I see on craigslist.

That said, you always run the risk of having to deal with some kind of health problem when purchasing a snake. If you think you'll be immune to potential health problems by purchasing from a breeder, check out Fauna's BOI...plenty of people have received sick animals from "pro" breeders...and if you think every breeder will take care of you if something does happen, again, check the BOI...it's not always guaranteed...

If it's a normal BP you're looking to pick up, they're a dime a dozen. I wouldn't pay more than a nominal fee...25 bucks or so...check it out in person. If it looks like it's in good health, most likely it is.

Good luck!