Hello,
At this point, superworms are perfectly fine for him! He just may not like the hornworms, some don't. Have you tried silkworms, they are white & he might like them. He showed interest then which is excellent. You can't always give up so easily on them, sometimes they just change their eating preferences. He is a bit older & they oftentimes before a little picky.
Your dad is giving up way too easily on him though!
Try more superworms then, to see if he will go for them. He needs some nutrition so I would recommend feeding him some more if he wants them. Once he gets more strength, then you can see about greens, etc if possible.
Let us know if he eats more of them. Have you tried the chicken/turkey baby food from the end of a syringe to see if he will lick that off? Or, you could put some on your finger & wipe it on his little snout & maybe he will eat that also.
OH, the moth will be fine, if it changes into a cocoon, you can just let it outside.
Tracie