I read this as they are looking to run the desktop over an SSH tunnel from a (headless) remote linux fileserver, hence my concern about latency. If this is the case, they would need to start the X environment manually, or maybe you could setup some checks to examine ${SSH_ENV} within .profile to try an autostart.
Another check is to ensure the user running ES, is in the correct group to access js events. Usually input
crw-rw-r--+ 1 root input 13, 0 Oct 3 19:05 /dev/input/js0