It's not unusual for them to go a month or so with out pooping. If my girl hasn't gone in a while, I know she will go when she sheds next if nothing else.

As for the piles of white stuff, it does just sound like urates. Ball pythons are able to reprocess the water from their urine, since they are from Africa and may not always get a much water as they need in the wild. They reuse the water from the urine, then all that is left is the urates, a chalky, white-ish/yellowish kinda solid.

It may be a good idea to put up a picture of some of the "white piles" or at least take some to the vet. Regurgatating is very bad for a snake and can really screw with their systems. Usually if they regurge, it is the whole meal, and with in a day or so of them eating. I've never had my girl regurge, but I'm pretty sure you would be able to tell what it is. From what I understand it stinks horribly as well. If your snake has regurged a couple of times, you have a very sick snake.

I would just take some of the white piles with you to the vet when you go, but it does seem to me at least, like it's just urates, which in that case is perfectly normal.