I don't think you need an open sky to have soils and a water cycle. You could have huge underground lakes that sit close to lava channels that make them boil. The steam would rise up through cracks and passages and gather in colder caves high above. And then the water would run down through other passages as underground rivers. And all soil on earth started from chemically dissolved minerals and is constantly recreated by rotting plants and dead animals. First you start with primitive lichens and algea that can feed on minerals, and as these plants die and decompose, you get the soil for larger plants to grow on.

Admitedly, this doesn't actually happen on earth at any significant scale, but for a fantasy world it would be good enough.
Or there might even be a surface where steam from the underground caves rises to the sky to form clouds, and it's the rainwater that comes down through the underground rivers. As long as there are no toxic chemicals that would poison the water, the surface could be completely inhospitable.

The energy from the sun can easily be replaced with heat from the planets core. But light does not. Any creature that evolved naturally in that environment would be able to see in some way that does not require normal vision. Since there could be glowing plants, animals that live near those plants might also very likely develop normal sight, as it is very useful. But they still would need to be able to find their way and escape predators when away from the glowing plants.