Hmm, actually the Minimenu shouldn't have started with the above sequence (I should have said that explicitly until after you manually log out of xfce.
Another experiment would be the following which should start minimenu from xfce by emulating the relevant parts of op_switchgui.sh:
$ echo startmmenu >/tmp/gui.load
$ xfce4-session-logout --logout
Since the actual minimenu runs fine only ~/.xinitrc (the lines starting from DEFAULT_SESSION, especially the while loop at the end) and /usr/pandora/scripts/op_switchgui.sh seem relevant (as skeezix said the gui settings just manipulates the DEFAULT_SESSION line in .xinitrc).
I sugesst adding some logging to ~/.xinitrc (e.g. replacing the line executing $SESSION with $SESSION 2>&1 >>$HOME/xinit.log, though I suspect it's not even getting to this point, possibly because /tmp/gui.load is missing) . This should give you some further clues to what is wrong on your system (I have a suspicion that there is something fishy with your /tmp).
Another experiment would be the following which should start minimenu from xfce by emulating the relevant parts of op_switchgui.sh:
$ echo startmmenu >/tmp/gui.load
$ xfce4-session-logout --logout
Since the actual minimenu runs fine only ~/.xinitrc (the lines starting from DEFAULT_SESSION, especially the while loop at the end) and /usr/pandora/scripts/op_switchgui.sh seem relevant (as skeezix said the gui settings just manipulates the DEFAULT_SESSION line in .xinitrc).
I sugesst adding some logging to ~/.xinitrc (e.g. replacing the line executing $SESSION with $SESSION 2>&1 >>$HOME/xinit.log, though I suspect it's not even getting to this point, possibly because /tmp/gui.load is missing) . This should give you some further clues to what is wrong on your system (I have a suspicion that there is something fishy with your /tmp).