Is it black, pink or simply not there?
Are you getting any errors in the console?

Both Fn+Backspace and Cmd+backspace will delete nodes in SF.
Cmd+backspace is the delete combination in the scene editor of Unity as well, which I would consider standard. Or did I miss anything?

Good idea!
I thought of it, but was concerned that it may look too cluttered with too many colored RGB outputs everywhere, but, I think it can be solved by making them show up when the cursor is near or while connected :)

Ah, is that a hard limit for GLES? Perhaps I should add a warning if that's the case

It seems to work fine on my end.
Is it only this shader or all shaders? If you make an entirely new project, a new scene, import SF, and make a simple diffuse shader, does it work?

Almost all the render platforms were disabled in that package, are you sure the shader compiled after you enabled platforms? (You may have to click the compile shader button manually)

Strange. Not sure what could be wrong then. I'll have to do some more research

It *might* be, but I doubt it.
Are you running deferred or forward rendering?