I don't really know how hard things are to create in Bryce
hmm rocks are quite simple in bryce, dunno about the waterfall

quite good, needs some uv maps expecially for the rock textures. add some particle systems for the haze. sky looks to flat - dunno how to fix that or if it's possible via particle systems/gizmos. add some more bits and pieces to get a more realistic look (maybe some plants on the rocks).