1.a rendering compare system à la maya or nuke.i mean store a render without saving it and put the old render on the new render, to see the difference after changing a value.
2.expressions or simple code to animate values without keyframes..here i think to Houdini and is "$F fonction"....with it it will be possible to create some animation assets for cloud and water.
3.A black/white masks render system to get only the clouds, only the light rays, only one population kind, etc....
4.An asset management tool to create a clean .tgc library...maybe with a internet sharing system.
5.call nodes faster in the network view. maybe by pressing a key and typing the first node name letter.