I would be careful about adding cat food to any feeder diet. It generally not recomended to use things such as dog food, fish flakes, or cat food.
The vitamin and protein levels or very hi for reptiles and can cause issues.
That being said, I add a scant amount of grain free, high quality dog, not cat food, to my dry gutload, to add vitamin A and extra protein to my roach diets, but I have years of experience and the percentage is 10% or less of my total mixture.
You need to be replacing the greens and wet food every other day, no longer, as molded food can cause poisoning to your animals.
I don't go through the lengths some do.
I use a plastic tote and I place an inch of finely ground pine park mulch, coir, or organic compost in the bottom, making sure is not wet and dry on the surface, but slightly damp, about like a wrung out sponge, 1/2" down. I stack 5 halves of egg crate or a few whole ones vertically, and replace as they get soiled, about every new batch of crickets or every month or so.
I don't screen my lids, I either leave 1/2" or so cracked or I place a section of plastic lighting baffle under the lid to allow air exchange, but prevent jumping out. I have no problems with deaths or odors.
I use eBay and often the crickets are offered with free shipping.