new ball won't come out and play

Keep in mind that this is a snake, not a puppy. He will never desire to "play" with you.

He sounds like he's behaving like a normal ball python, and your friends advice of soaking him to get him to play with you is just going to be more stressful to him than anything.

Ball pythons are not the most exciting pet to have, they do spend most of their time in their hides. They really have no desire to interact with you. The interactions happen because WE desire them.

I've yet to hear of a ball python that escaped from it's enclosure come seeking out it's owner because it wanted to be with them.

Robin made some excellent points. While snakes are fascinating creatures to own, they aren't the "normal" type of pet or even one of the better display type snakes. They are shy, very nocturnal snakes that like their hides...a lot.

Speaking of hides, I would suggest you might want to rethink that tunnel. Providing any piece of cage furniture that your snake can get into but you can't get it out of, may in the end cause you some problems. Also it's likely to get nasty if the snake toilets in there and it's not easy to see in or clean up after the snake. A hide that will both fit your theme but has an open to the substrate bottom is likely a better choice.

Snakes do drink water, they also pee in two ways - liquid urine and solid white urates as well as defecate. :)