I'd get rid of the red light, they like it completely dark at night. Substrate is one of those hotly debated topics here- I personally do not use any substrate for the reason that it is easier to clean the bottom of the cage without it. You'll get dead feeders and poop in it coupled with the dampness it can get germy. As far as humidity, the enclosure needs to dry out between mistings, your humidity levels will spike after misting then go down as the plants dry. A constantly damp enclosure can lead to respiratory infections. I'd also limit the mealworms in his diet- they can lead to impaction as they are more shell than "meat". Well gut-loaded crickets are a better feeder. Other choices are silkworms, hornworms and dubia roaches. Congrats on your new guy- he is a cutie!