Don't know if it's contraindicated, but I've had ~/.Xdefaults symlinked to ~/.Xresources for some time. At one time and possibly now, Openbox needed Xdefaults to run properly. In fact, it's still there in xinitrc:
Code:
openbox)
exec ck-launch-session dbus-launch openbox-session
xrdb -merge ~/.Xdefaults
;;