He can't keep roaches, it is Canada we are not allowed

ok you need to cover 3 sides on your enclosure and look into bigger tank soon
humidity. It gotta be 70-80 with temp at high 80 it is hard to do, they can tolerate that temp, but will feel better close to 80 during a day.
Super worms are fatty and have high content of chitin, not as high as mealworms but not by much, for a a big frog one or 2 wont't do much, but big quantities may cause impaction, so you better slow down on these. Crickets, night crawlers should be a staple. And make sure you supplement them 2xweek with ca/vitd3 dust and once a week multivitamins.

Never seen that substrate here, but if that says coconut fibre it is fine. When you expand it make sure you use conditioned water, same as for your water bowl.
Also I would suggest to put some sorts of hide, plant may be, even hanging would do.