Window managers bind orthogonals (keyboard shortcuts, window manipulation, window decoration) which should remain separate.
Can one really run X11 without a window manager? Most of my time in X11 is spent using URxvt + screen and surf (webkit based browser). All I really need is something to manage keyboard shortcuts, and a way to manipulate windows when needed.
I hacked together a session manager, alt-tab, window resizer, and a howto and posted them on github at https://github.com/patrickhaller/no-wm
I added a focus manager for misbehaving apps that exit without reset'ing focus. You can also corral bad apps by calling x-alt-tab after the app exits. That needs to be scripted though, because at that point, a window that no longer exists has the focus.
At this point, no-wm seems complete. famous last words....