I'd go with Aldaran's idea about dividing it into thirds. Set keyframes at 0,120,240,and 360. Then there's no confusion over which way it should turn. Rubycon

I think its definitely something you would need to do in post. A video editing prog like Premiere or Lumier Suite should be able to do motion blur. It would allow you to apply blur to just the layer that you want. Rubycon

You mentioned that you try to do as much modelling in Bryce as possible. Does that include a lot of Boolean work? That will slow things down dramatically. If need be, model in another app and import. Rubycon

It's a very nice pic. I like the terrain. It has an other-wordly feel about it. I agree with Alleycat about the sense of scale. I think what it really needs is a focal point to attract the viewer's eye. Those two buildings to the left are the obvious choice, but they're too dark to be seen. Some windows would make them stand out. And if the light coming from them was blue-ish, it might be a nice contrast to all the red. Rubycon

Kinda A10 / FY18 hybred, eh? ....with a hint of an SR-71.

You can find them here...
http://home.europa.com/~keithr/Crossroads/index.html

http://www.righthemisphere.com/products/3dexplore/downloads/index.htm

Apparently 3D Exploration is now only a 30-day version.

Rubycon

I used to get the same error message when importing from Ray Dream Studio. You need to load the object into a file translation program and resave it as an OBJ object. Crossroads and 3D Exploration are two popular ones. Rubycon

They're still in biz. The next one will be out in late March. I think it only comes out every other month. Rubycon

I did a quick test using the Gradient Fill tool in PhotoPaint. I had the Steps set to about 80. That looked pretty good. Didn't need any posterizing. I'm not sure how many courses of stones the actual pyramids have. Must be hundreds. Don't forget to set the terrains Grid pretty high (512, or 1024).
FYI, the sides of the pyramids slope at 51 degrees, which means the height is about 62% of the width. They were originally covered with a smooth veneer of white stone. The pyramid of Khafre still has some of that veneer on the top of it.

Rubycon

Looks better already. The lighting off the top of the liquid also improved. You can adjust the sharpness and darkness of the shadows by making the light dome larger or smaller. Putting a texture on the table will help hide those shadow lines. The more lights you use the better the shadows, but the longer the render times. Rubycon

Soft shadows can do a lot for creating realism. Take a look at this tutorial by Necati Pamuk for simulating radiosity. http://www.bryceanworlds.com/pages/simulated_radiosity1.html Rubycon

Wow! That's pretty convincing.

Maybe you could posterize it in Photoshop. Or just reduce the color depth. Just thinking out loud. Rubycon

Not sure if this is what you're looking for, but this woman has two tutorials for creating roads on terrains. http://calyxa.best.vwh.net/pearl/tutor.html See the Flat Roads and Swooping Roads tuts. Rubycon.

I think that Bryce aligns the object's Z-axis along the path. Your object apparently has the Z axis facing the wrong way.
Don't worry. You just need to use a null object. Create a cube and position it so that it's Z-axis is aligned along the path. Link it to the path. Now link your model to the cube. When you move the cube along the path, the model will go along for the ride. (remember to shrink the cube down so that it's hidden inside your model.)

Rubycon