Ok, that was it... I just hadn't correctly set up my skybox. Just set mesh size to 0 or use Create Meshes. I suppose it would've been more intuitive if WED didn't start a new level with a mesh size of 1000 and create meshes not checked.

I'm learning more and more about how to do these things in A7, but pretty much only through rigorous forum searching and patching together what I find :/