Very nice work. We do intend to provide better animation tools, a timeline and similar standard features. Hopefully it will be possible to add a "height above terrain graph" similar to the one in Terranim as I agree this is very useful.
The issue of the sun showing through the mountain is a bug which currently can only be addressed by turning on Raytrace Shadows in the Atmosphere Quality tab. Unfortunately this increases render time a great deal. This shouldn't be necessary in the future, but for now you could simply re-render those specific frames where the problem is visible, with the Raytrace Shadows option on. You could even do a crop render of just the sun area to make it go faster.
- Oshyan