Welcome to the forum. Might be time to start weighing her and keeping track of her mass so you can see how her bodyweight fluctuates. What are the temps on the cold side?
Licking the powder is normal. Not eating for 3 days isn't too much reason for concern. If you'd like you can track his weight with a food scale.
Everything you're describing sounds relatively normal. You can give him a shallow bath if you think he's dehydrated.