Really good job. You are very committed in spite of it being an impulse purchase. Most people would quickly learn how much time and money it cost to care for these lizards and give up.
These lizards are known to spend most of their time on high places so that is not unusual. They are semi arboreal and he probably does come down when you are not watching.
One important thing to keep in mind is that these lizards are known to run into the glass. I see that your tank don't have that issue but just fyi for when you upgrade. Speaking of which, this little lizard will grow to be pretty long so a tall, long enclosure that holds humidity is a must, something that is not easily available in pet stores. You may need to purchase a custom made tank or make your own. It must be tall enough for climbing, and wide enough to move around on the ground as well as enough space to accommodate a large water bowl and for drying.
I am not a fan of red lights for night use as most lizards can 'see' it. I think it stresses out the animal at night.
UVB lighting is super important. Anything on top of a mesh lid requires something strong, like a T5 Reptisun 10.0 HO. The mesh lid filters out about 60-70% of the rays he needs. And for the same reason, the branch or highest climbing area where he can bask should be no higher than 10-12 inches from the light to avoid burns.
Watch out for the fish feeders. If you are getting the goldfish, they are known to carry worms and other parasites. My husband kept 3 of those for the longest time, and then one day, they started to die and we found their guts were filled with worms (Some were even poking out of the anus). If you must feed fish, I hear guppies are safer.
I like to be honest with people and here is my fair warning to you: Chinese water dragons are expensive lizards. The size of the enclosure, the husbandry and being an import makes them a challenge to keep. However, you can do it as it sounds like you are up for that challenge.