1. Those messages are as Magic Banana says in the file /var/log/messages ,
look at them with
sudo less /var/log/messages
in Terminal
2. If you want more detailed messages use either of the commands apt-get or
aptitude with the appropriate parameters. Again from Terminal. You might
find using the command 'script' first, so you get all the output in a file is
helpful.
Lastly if you search on the Internet you will find plenty of pages where
people report their machine not powering off after a shutdown command as a
bug. These people would not be very happy with your suggestion of a pause
and I suggest that is true for most users. If you absolutely need to capture
every last message then get yourself a serial port and build a custom version
of the Trisquel kernel package to use the serial port as console and record
the output on a second computer attached to it. That's why those messages
are there, for the other non-x86 architectures that come with such a console.
