Welcome to the forum Peat moss is different from sphagnum moss because peat is ground up and will look much more like cocoanut fiber than moss. Peat is usually more acidic than other substrates. If it is organic and has no perlite, fertilizers or added chemicals, its safe! Cocoa fiber is one of the most commonly used substrates for frogs and is one of the safest options, its great for humidity and burrowing. If it is made for gardening, you may have to swat away small gnats but they are harmless. The "round balls" you see are Lightweight Expanded Clay Aggregate or LECA for short. They are commonly used as a drainage layer for planted tanks for excess water to drain into a small resivoir. I would recommend it over pea gravel because it's much lighter and let s the water drain better in my opinion. Cocoanut husk and peat will be fine for plants you choose