Morio Worms will eat just about anything as far as I know. I use spinach, collard greens, mustard greens, carrots ect. as well as any premade gutload I may have on hand. They seem to love Cricket Crack. I have heard of a few methods, and I am not sure if mine is even the recommended one, But I remove them from the flakes they come in, and I put them in a tupperware conatiner with vent holes cut in the top. I then shred up a good amount of the greens and what not and throw it in with the worms. Once I out the food in they go to town, and by the next morning you should notice that the worms seem significantly fatter.
The husbandry for Panthers and Veileds is really similar. Mine are acctually kept with identical care and no problems. It is said that panthers like slightly cooler temps than veileds, and a bit more humidity.