The water should be either treated tap water or bottled spring water, the substrate is good and the humidity levels seem okay. The tank is big enough for now but as the frog grows older it will need a bigger, taller tank. Also, a hide may be good for them so they don't feel they are being watched all the time. Getting a hide would probably rescue the stress of the frogs.
For the crickets you should dust them with the calcium/vitamin,powder, not every day but maybe 2-4 times a week. I'm not sure why they wouldn't be eating a lot, maybe someone else could help?
hope it helps!