I've done part of what you said. things were weird. I am writing this in gmail in my xp box and working the linux box,.
I just did a full reboot. using startx mod xinitrc did not work. startx fvwm or startx fvwm-nightshade does come up.
but had weird operations. so I rebooted.
I had foujd a problem with a simple gedit of a file. hints led me to some /run/..... file that was owned by root. my normal user setup is watson.users.
did a chown watson.users then problem message changed to fns something. I just did a ls -l of /usr/local/Fnwm-Nightsahade-0.6.8/fns-install_0.6.8.lst and found fns-install_0.6.8.lst is also owned by root.root.
xinit fvwm or fvwm-night shade got rid of weird but still had funny edit problem
NOTE: I changed the softlink of ~/.fvwm-nightshade/.
lrwxrwxrwx 1 watson users 54 Apr 21 10:27 .layout -> /usr/local/bin/../share/fvwm-nightshade/layouts/G2like
copied my .fvwm2rc file to ~/.fvwm-nightshade/.
fvwm-night shade startx just like fvwm, but had window hints like nightshade.
I then returned links and nightshade starts. I am working on list of how to fix.
I am still starting xinit which `fvwm-nightshade` I did fix fns-.... onership.
I looked at xinitrc I apt-get twm. I can startx fvwm or nightshade, but I cannot start an xterm or a terminal
that is part of the weird.
so I'll reboot, ok I start fvwm or fvwm-nightshade with xinit `which ....`
The menu xterm shown starts in fvwm and terminal starts in fvwm-nightshade.
AddToMenu RootMenu "Menu 3.11.0-18-generic" Title
+ "XTerm" Exec exec xterm -sb -sl 2000
but after I attempt startx fvwm or fvwm-nightshade the above command flashes xterm and it dies.
Same with terminal in fvwm-nightshade.
but fvwm menu items where there is a -e su user asks for password and lives with correct password.
+ "XTerm root" Exec exec xterm -sb -sl 2000 -bg "pale green" -fg black -geometry +50+1335 -e su -m
that's it for now.
tom watson.
PS I be sending along a description of the other oddball stuff concerning starting with vertical displays.
fvwm and fvwm-nightshade do basically the same thing.