A bite from a baby BP doesn't hurt at all; it feels like a finger prick. Their teeth are so small that you most likely won't even feel the bite. When handling/picking up the snake, try not to be nervous to pick it up or handle it because if your nervous then the snake will be nervous too, making it more prone to bite. If you are calm, not scaring it from quickly picking it up, and handling it gently, the snake will be calm. IMO, the 'S' shape is just how pythons are, and means nothing. You can tell when they are pissed or having a bad day because when they are doing the 'S' shape it looks a lot different: The 'S' is tighter and more closer to the body and (what I've seen) the snake's head seems to look upward a little (the head thing may mean absolutely nothing, but when I see a pissed python their head is normally a bit upward or looking up slightly).