Strange really, I can't see why you would get that error.

Anyhow, you probably don't want to use clamp0-1 right after sin, that will give you a bump, followed by a flat line, then another bump, etc.

If you want a sine from 0 to 1, use the remap node instead, and remap from -1, 1 to 0, 1

Oh, yikes, that sounds scary. Seems more like an error in Unity's translation from CG to assembly

Do you have them in this order?

Clamp0-1 <- Sin <- Time

Do you mean in the shader or in the node previews?

A code node is planned, but I'm not sure if there will be a custom node system. There are however plans for making nested nodes, which would then be able to act like non-nested nodes in your shaders :)

Edit: A code node has now been implemented in Beta 0.28

Marmoset's cubemaps are pre-baked, they have already made the MIPs beforehand.

If you're doing real-time cubemap rendering, you won't get convoluted MIPs along with it, just the highest resolution render

It's tricky to do in Shader Forge anyhow. It involves sampling your texture multiple times

This isn't really a question for UserEcho, but, it is possible, but it's expensive to render. (As in, really expensive)