Re: editors, sometimes you simply cannot get away with multiple windows in place of panes, unless someone decides to do insane amount of work just to make editor integrate-able(?) with screen/tmux/whatever WM you happen to use; vimdiff would be a great example, as it is basically impossible to use it without panes.
I've decided to only use a tiling WM for all window/pane management, and stop using anything else, as much as possible.
So I abandoned Gnome3->Terminator->tmux in favor of bspwm->urxvt. I don't lose the functionality that I had before (tiling terminals), and I'm using much lighter-weight tools and less of them. I love it.
Oh, and as for editor tiling... Yeah, I still have to tile buffers in Vim/Emacs, but only because I prefer the editing workflow in that case (all my context / session / environment remains the same). I suppose I could have lightweight clients, but I haven't really looked into it.