I may not be able to answer specific problems,.........but I can give you a general way of looking at things, copmosition wise. The thing about 3D (not just Bryce but all 3D), is to look at it as if you are working with a stage set (like live theater), it's like Trompe-l'œil, which means "fool the eye" , you want to build your scene so everything "looks right" for the camera, but may not be accurate "to scale". This will save alot of time and trouble. This goes for lighting as well as objects,.......download madmax's Zenith Sunlight Systems from freestuff, (if it's not available anymore, lemme know and I'll send the zip along to you.), then you can, turn off the sun in your scenes and use the Zenith system for a more natural softness and bleed to the shadows. I use this method in most of my outdoor scenes. Anyway,..........wish I could be of more help. And BTW, the only stupid questions are the ones not asked.

"Any club that would have me as a member is probably not worth joining" -Groucho Marx