This took ages, but eventually an xsession script to make that nifty x2vnc run automagically on startup.\
Trick is to accept that a local
# visual indicator in case I start X as root
if [ "$user" = "root"];
xsetroot -solid orange
else xsetroot -solid darkred
#do x2vnc, telling
x2vnc -east -passwd ~/foo bar.biglig.com:0 &
And it all seems to work.
the xsetroot stuff is of limited use, so I took it off.