Hi there, you can add greens like kale, arugula, mustard, turnip as well as [ sometimes ] snap peas, fresh chopped green beans, squash. The main 4 greens I mentioned are the most important. Don't bother with spinach, radish, grapes, cucumbers, apples.
Zayde's behavior is nothing concerning, if he loses his appetite or has consistently runny stools you might have him checked for parasites, other than that just be patient. Not all beardie's are cool + calm.