Your comments

There's not really any way to avoid that as far as I know, and it has nothing to do with SF itself I'm afraid. SF has consistent line endings in the files it generates, but it has no control over what your version control system might do with it if you work between platforms or run diffs/merges
I don't think that's possible in that case, I'm guessing the shader is simply too complex for the platform in question.

So, in general, the closest you can get, is to enable d3d11_9x and enable SM2.0 in the experimental settings.
I'm not really sure what you're trying to do, that isn't already possible. You can already use multiple UV coordinate nodes with all the different UV sets, with custom data inside.
This has already been added, as of 1.14. Look under the blending settings
I'm guessing this has to do with how the mesh is UVd. Try looking at it with a quad instead
That's a pretty good idea, I'll consider adding something like that
The error in this case is actually correct. I guess the issue is rather that it allows you to make the connection in the first place.

UVs are two-component values, for U and V, not three components. Right before the texture UV input, make a component mask node, and mask out R and G from the lerp output, and use that as UVs instead
I'm not sure what use that would have. Just make a relay node and comment on it?
There is already one - Reciprocal :)