Inbreeding, for most animals, isn't really that bad. Inbreeding can give you several mutations with BPs which I really like. I believe you can only get the super forms by breeding co-dominant traits, though (ex: Pastels, Mojaves, Lessers. The super form of a Lesser would be a BEL, or also known as a Blue Eyed Leucistic. Anyone correct me if I'm wrong with the co-dominant thing..).
If you do inbreed BPs, inbreeding only a few times (generation after generation, like offspring to mother or father or brother to sister) is just fine, but if you keep on inbreeding generation after generation the snakes will start to get dumber and dumber as you keep on inbreeding, which can also result in deformities like kinks or missing eyes, and that kind of stuff.