Okay......you didn't miss anything so I am going to try to do right by you with the same. It's gonna be a novel......
Let's start with the Water:
it's one of my pet peeves. Distilled water can be fatal to the frog because it has NOTHING in it (no minerals or vitamins) and will leech them from the frog. We use & recommend to use de-chlorinated water. We use Prime as a de-chlorinator, but almost any will do, you can find it in any pet store pretty much.
Substrate :
We prefer coco fiber in the finest shred you can get, just inspect it for rocks or large solid clumps that could be ingested accidentally.
Lighting :
We don't use it ourselves, but we breed them. For looks, a Red or Blue light is cool for decoration & viewing purposes. Remember these are nocturnal animals and will get required vitamins & minerals from their foods & supplements.
Humidity & Temps :
Humidity should be kept in the upper 80's and temps should vary Cool to Hot no lower than 76, no higher than 85......at the lower temps they will attempt to aestivate (go to sleep, hibernate) and will shut down until temps are more acceptable. You can use plastic wrap on the tank lid to cover 75% of it to try to keep humidity up and it should also help to keep temps steady. You will need a UTH (Under Tank Heater) to place on one SIDE of the tank.....do NOT place it under the tank floor.......they will dig down right over it & possible cook themselves that way.
Enclosure Size:
This will depend on the size of the frog. We usually keep our juvies in plastic tubs (again, we breed them and space is an issue for us). If the frog is small & the cage too large, they will stress out. Looking at your photos, I think the 10 gal is just fine. I think the issue may just be temps & humidity.
Food :
In our experience, the nightcrawlers/earthworms are the best staple food nutritionally speaking.....a varied diet is best all around though. Use the worms as a staple and add crickets, horn-worms & dubia roaches if possible for variety. You can offer a pinkie mouse as a treat maybe once every 3 months, but we don't really recommend it. The mammalian proteins are difficult for them to digest and if feed this too often will result in Fatty Liver Disease which is fatal. You can also order some of the Samurai Food. It is a powder that you add water to and is a complete diet for them. We have yet to have a frog refuse it. Also, feed in the evenings....again, nocturnal frogs.
Supplements :
Dust food items with calcium w/D3 twice a week, vitamin supplements twice a week and not the two on the same feeding. The other days, don't dust at all. They get used to routines & will adapt to a schedule fairly easily.
I don't think you have anything to worry about yet. If you can correct the issues & give him/her a few days to acclimate, I think things will turn around for you. Once the frog gets nice & warm & sweaty, it's appetite should kick in. It may take a bit of teasing with the worms to get the frog to open it's mouth for them, but just keep doing the Zombie Dancing Worm Dance with the tongs and tickle it's mouth with the worm until it opens it's mouth out of instinct or plain old anger. Hey.....it works for me....even with the tiny just emerged froglets!!
Your other questions:
Shedding happens often. You will see the frog look like it is trying to take off a body suit....back legs rubbing over the head and sides.
Cleaning : Spot clean every other day or so (remove poop clumps) and do a substrate change once every month and a half.
Feeding: I covered the schedule stuff. I don't think force feeding is an issue yet.
Size & Life Expectancy : Size can be 3 1/2 inches (usually males) to possibly 8 inches (a huge female) This goes for the C. cranwelli at least. The ornates get bigger. As for life expectancy, they can live up to 14 years.....i believe there is one at a zoo that is over 20 years old??? It will all depend on the husbandry & the individual frog too.
Misting/Soaking : Make sure he has a water dish and access to it. Make sure it has clean water in it and is no deeper than the frog's chin. They are terrestrial and pretty much are lousy swimmers....LOL. Misting is needed to keep the humidity up with the screen tops, but you don't need to mist the frog directly. It just tends to tick them off and is a source of amusement for us humans.
Poop : Normal poo looks like little brown sacks......almost like an earthworm head chunk. If need be, I will take pics of poop sacks tonight during cleaning/feeding time for you.
It took intelligence to ask for the help without allowing pride to stand in the way. I applaud you!
I think I covered it all, but if I did miss something, let me know! I'm sure others will chime in. This forum is a great place for sharing info!