Almost there indeed...
Just fixed the problem with the restart issue

Great....
I'm not sure I fully understand the issue with the domain information.
My /etc/hosts only has 2 uncommented lines
127.0.0.1 localhost
127.0.0.1 BlackBox BlackBox
Of couse, "BlackBox" is my hostname in /etc/ HOSTNAME also.
Hosts should look like this:
127.0.0.1 t-42vl.ibmpeers.net t-42v
And HOSTNAME should have this form:
t-42vl.ibmpeers.net
I'll try another reinstall and see if I can enter both machine name and domain name. If so, it may simply be a matter of making the prompt clearer.
If its left untouched (which it will be using the TUI install, since in the alphas at least, it is jumping past the network setup stage), it defaults to vector.linux.net (if I'm remembering correctly....)
The GUI isntaller will create the necessary directories if you tell it you want to mount win partitions at boot. It let's you choose which dirctory to mount them too (defaults to /mnt/<dev address>)
No problem. It just seemed a bit odd - TUI install creates /mnt/win, but GUI install doesn't.
And I have no clue as to why the XFCE quit dialog problem.
Help

Sorry. I'm wondering about something like a difference in the way /etc/sudoers is set up, since so far as I know, that would be what controls who can access the shutdown command. But I can see no reason that should be any different when run from TUI or GUI install. I'll try another couple of installs in the next couple of days and see if I can spot what the difference is between the two install types. Let you know if I find anything.
paul