i now have 5 months keeping kinyonga multituberculate in captivity, no where near some of the other keepers, but keep in mind that those keepers most likely now have and have been captivating CB K. Multi. what you have is 99% most likely WC, and with WC's are complications other than condition and parasites. They are fussy eaters with not the biggest appetite. My guy hates silkworms and eats a hornworm on occassion. He does like crickets but doesnt eat many at a time. He loves superworms, wax worms, meals and i fed him his first dubia roach today.
I advise that you try and not get frusturated with seeing all of the food in the feeding dish/cup/jug. this is very unfamiliar with WC species, as they hunt for their food in the wild. They also seem to not like a population of bigger insects like crickets, supers and roaches in one confined area. Thomas will just stare at the insects all day, and the moment i let one loose, he'll go for it. also, on the note of being picky eaters, in the wild where the come from in tanzania, they dont have some of the feeder insects that the trade offers, such as hornworms and silkworms, but will eat grubs since our grubs look like that of where they come from. this is a hint on why they dont like some foods we offer.
all i can say is be patient, offer a variety, and wait it out. it will probably take a long time to cup feed train him, but to ensure he eats, just free range. 4 crickets at a time or one worm at a time. he may not even want to eat with you watching him.
on the note about the waterfall, like the other guy said, its a breeding ground for bacteria. its a big NO NO here in the forums. yes, i admit, they look esthetically awsome, but its not worth the risks of the animals health. im actually upset that these companies market (safe and easy to use, quick clean up, great filtration) when these products offer nothing. anyways, 3-4 mistings a day for F. Multi is good. their humidity can go down to 50% in the day, but needs to be relatively higher at night. they drink alot, and for montane species, hydration and water is very important to them. a ZooMed "Big" or "Little" dripper is the absolute best thing you can purchase along with your mistings. or if you get crafty, you can make your own dripper with a container, an aquarium air nozzel, and some air tubing. just do a search to see how its done. or just save yourself the time and buy a dripper. i realy do not think it is necessary to put liquid calcium in his water, unless he isnt eating at all. and follow the free range guy, he WILL eat. you can however, declorinize your water with aquarium solution or zoomeds reptisafe (SAME STUFF IN IT) just make sure that you have electrolytes in the solution.
anything will work, and your two-horned will get the jists of things. how long have you had him for? if it is recent, then he is most likeley still acclimating, and will be for the next little while. my guy STILL is uncomfortable with my presence.
but i hope this post helps you out, and i appologize for my very long reply.

best of luck
- Phil