Snakes produce three types of waste product....feces (poop) which to me pretty much looks like small cat turds (or not so small, depends on the snake lol), typical liquid type urine and urates which Lawrence explained to you are just a part of their urination process. The urates come out pretty soft and "puffy" then hardened up and dry out fairly quickly. One of the many joys of snakekeeping is learning how to chip a urate out of the edge/rim of a snake hide. I swear some snakes drop their urates in the MOST inconvenient spot they can find.

As far as the change of behaviour/aggression it sounds like it's stress related. Remember that snakes react to change rather poorly and it can take time and become sort of cumulative. Your snake went through a move, humidity issues, a long bad shed and so forth. It stands to reason it's probably had enough and is now feeling defensive and out of sorts.

Personally, I'd just make sure everything in it's environment is stable and your temps/humidity are bang on, nice hides, etc. and just feed it and gently start to reintroduce yourself to it's world in a few weeks. If you need to wear gloves by all means do so until it calms back down. Just be calm, gentle but firm in your handling (not hesitant....I swear snakes sense hesitation and nervousness in humans), try to make it a calm experience for you and your snake. Repeated short, calm handling experiences usually result in the snake getting the point that nothing is about to hurt it. Some never adjust to much handling but most BP's accept a reasonable amount but there is never a guarantee that way.

Everything about ball pythons seems to be about patience...lots of patience.