I have bred these for a year now...I feed smaller ones to my collareds and chameleons, and med size to my Bearded....she chomps them before they ever hit the bottom! I would not feed tons of them though, and freshly molted would be best I am thinking. and as for keeping them...
They do NOT require humidity! That will lead to molds, mites, etc and all kinds of nasty things to deal with!!!
HEre is how I keep mine...I have 1 inch of birdseed in the bottom of the container...I use my own water bites (make my own), and put chicken feed crumbles in a shallow bowl (non-medicated!). EVery now and then I toss in some greens. I also give them toilet tissue tubes to hide in and they love those...and my colony is thriving...THRIVING....am almost over run with them!