Id just keep your humidity up. Yes I would look into getting a substrate other than moist paper towels. As I mentioned before tree fern or coconut fiber. Paper towels are generally really good for temporary transport / quarantine tanks. Other than that it looks like you have a great set up. Eventually if you want to challenge yourself. Look into getting a large leafy plant in the terrarium in combination with the artificial and see which ones they prefer to stay on. I noticed my tropical frogs preferred to stay on the glass rather than the artificial plants, so i invested in a few live plants. They love it. I like your rock bed though.. That is very unique and Ive never see that. Id say more intermediate level due to the moisture control. I have yet to see an advanced frog on a care sheet. But i would expect anything that needs running water/ live vivarium only frog would be in the advanced section. I like how your going to go into a water bottom. Just keep in mind they will need things to climb on in the water to prevent drowning just like the whites tree frog. Keep us posted on your frogs. But I'm sure they are just fine =) -CJ