Re folding: what about inherited codebases, via github or your company or whatever? That seems to me to be the vast majority of source code being read / edited in the world, and odds are you can't simply change it on a whim.
I think that pain is a great motivator to refactor the code base. I understand that pain, I have been there. But coming from an IDE that supported code folding, I can say two things about it. First, it only helps marginally. Second, it makes occurrences of large files even more prevalent.
