1. I'm not sure. I'll wait to hear other people's answers.
2. It might be a little much. I've heard twice a week as a recommended feeding frequency for adults. But I'd just look at the frog and see. If his ear rolls get big I'd cut down on food.
3. The time should be okay. I'm pretty sure it doesn't matter.
4. Probably unless it starts to smell bad before then. I'd remove any poop I see immediately. (You do have plain substrate, not a planted tank or water?) Water needs to be changed every 1-2 days though.
5. I think it's a bit too small honestly. Tree frogs really like to jump around at night and White's need all the exercise they can get. A taller tank might lessen the urge to rub their noses on the mesh.
6. Big chunky stuff like orchid bark can get swallowed and lead to impaction. Honestly fine ground coconut substrate can lead to impaction too, I've heard, but it's a lot less likely. The plants and log are good. Plenty of places to hide.