well, one important note:

>> .  Ctrl-R will give me a pointer that's frozen in the

I bet you think ctrl-R "restarts" the display (kills the server, has
xdm restart it.)  It's reasonable to think that, since after all the
xdm man page *says* that's what ctrl-R does.  However, if you look at
the actual resources, or even the example further down on the xdm man
page, it shows that ctrl-R is *actually* bound to "abort-display()"
which tells xdm to "kill the server and stop managing this display".
Needless to say, it's doing that, and having the -HUP start it up
again is consistent with what is implemented...