1. I would bring the temps up to the lower 80's. These frogs are found in New Guinea and Cape York, so I think a temperture range of 78 - 82F works well. You can drop it to about 70 at night, but no lower.
2. Go with the book.
3. Taller is always better.
4. Heat lamps can be very drying. I keep most of my frogs in a warm room, but I do have some frogs in my living room where it is cooler. The rococo toad has a heaty pad on the side of the tank and that seems to work well.
For more care info see the White's treefrog care article, as the care is the same for both species.