Ah, x.org usually has TCP disabled globally these days. To allow it to the extent that xhost will do anything, you need to run X with the -listen tcp option.
Did you use ssh with -X option (or any option relating to DISPLAY exporting, depending on your platform & ssh version) ?
Did you enable all corresponding X11 forwarding stuff ?
You need to use whichever fence device is appropriate, not look for easiest. By your question, I'm guessing that you may not understand what the fence device is. Pacemaker needs to be able to force...
SYLOGIN.COM gets run every time a user logs in. You DEFINITELY don't want to put it there. Any time a user logs out, any disks privately mounted to that process are automatically dismounted.