I'm arranging windows the way I want them on my desktop, specifically oclock, which by its nature never accepts focus.  According to the docs on xfwm4, window manager operations (such as ctrl-shift-alt-arrow to move it, or possible mouse actions) are delivered to the focus window.  This means that windows which don't accept focus are unmanageable, and my oclock is going to stay where it is, forever (or until I do "kill $PID" and restart it with an explicit geometry; I thought we invented window managers to do this kind of thing).  
    Feature request, alternative 1: if a window is incapable of accepting focus (or lacks a titlebar), treat the entire window as if it were a titlebar.  Right click would elicit a window manager dropdown menu; left click and drag would make it move; if the cursor entered it (focus follows mouse) or you left click on it (click to focus), keyboard shortcuts known to the window manager would cause the corresponding actions, e.g. alt-F4 closes it.
    Alternative 2:  If that's too radical, have a special keyboard shortcut or window manager menu choice causing the window manager to display a distinctive cursor, and the next window clicked in becomes the target of window manager actions, as if it had focus, even if it refuses to accept focus due to the click.  I'm thinking along the lines of xkill or xwininfo or xwd.