Hey Steve. I also have the xhale02. Been using it for two+ weeks now and I freaking love it. I always have mine fully assembled unless its charging and have had zero problems, thus far. I used to clean my atomizer by dry burning it every night, because I thought its what you're supposed to do, but this forum has convinced me to just do nothing with my atty. As for the carts, I have found, for me, they are equivalent to about 3 to 5 analogs. I did do the manual refill myself once, but it took so much time and was a pain... now I just drip my juice right onto the atty.... soooo much easier and a better vape. Now I only refill carts for convenience, such as when Im driving.
basically, as far as maintenance, do nothing. Should anything break, replace it with any 401 piece as they are compatible and 70% cheaper than the Xhale pieces.
When it comes to carts... just DONT do it. I say drip/dip your atty with a few drops of juice (about 1 analogs worth) and skip the prefilled carts, they're a waste of money. Buy a good juice and refill your own if carts are what you want.