I tried my hand at this and failed miserably with the curve method - couldn't figure out the distortions or how to get things to get where they need to be exactly 32 frames later. So I did it another way - there's a nice add-on for Blender called ARew0 which lets you make fake "arrays" of objects but with all their keyframes offset in time. Perfect for belts and another things moving in formation. So you just set up one "slat" of the belt and then make an offset array of it 8 frames behind (or however many you want).
There's another nice add-on called Render Border which gives you easier control over which section of the rendered image is automatically masked off, and whether or not you want the output cropped - perfect for things like this (and other stuff like working animations etc.) where holdout masks might get antialiased.
I discovered you can use Blender to render the whole sprite sheet without having to do any rotating/mirroring separately. Just keyframe the camera and rotate to get the different angles. When you get to the weird mirrored curved belt, set one of the camera scale axes to -1, that produces a mirror image effect. Don't forget to set it back when you move on to the next series.
I also managed to figure out the end patches. I don't think I've ever spent so long tearing out my hair over something that is about 4 pixels wide. The end patch is easy, just mask off the last 7/8ths of the tile (it looks like Wube did something much cleverer with the belt actually bending and rolling away underneath itself, but that's beyond my skill and likesay, it's barely visible). But the start patch is, for whatever reason, 4 frames (a quarter tile width) out of phase with the end patch. So you have to mask out all but the 3rd 1/8th of the tile. Nightmare fuel.
Lastly you can make things look more 3D very simply by giving it a dark glow as a kind of directionless shadow (belts aren't orthographic like most other stuff is). In the compositor, get the alpha channel, blur it, multiply it by a small amount, then add it back to the original alpha channel. Simples.