They do not need that much choice. In the wild they do in fact stay in the same spot for most, if not all of their lives.

Too many choices will just stress them out, the same as too large of an enclosure. Is he an adult, or sub-adult, or juvenile?

That tank is too big for even an adult, and I think it would be beneficial for your ball python if you would add less options, and make more comfort.

I do not think it is normal for him to always be on the cold side. Even ones that prefer the cold...don't like it all the time. If he doesn't move, something is probably wrong.