No, the odd patches of scales are not necessarily normal. Is it possible that it is just dried urates or is it indeed the scales have become discoloured? Try washing the areas gently with warm water and see what happens. If they are really the scales, I'm honestly not sure what would cause that, not dry skin, possibly a bacterial or fungal problem. You can try treating them with betadine solution 1-2x daily, as it takes care of both types of problems. Smelly snakes can be caused by either unsanitary conditions or by sickness. If it is caused by filth, then it will come off with her next shed. You can try and give them a bath if you catch it fresh, but it seems to just soak right in their skin, so likely wouldn't help much now (if that is indeed the case). Good luck with your new little friend, hopefully it all works out ok. Next time try buying from a more reputable source, as to avoid problems