I've started from the top down...
The first two errors are:
Use of uninitialized value in concatenation (.) or string at /var/lj/cgi-bin/ljdefaults.pl line 43.\nUse of uninitialized value in concatenation (.) or string at /var/lj/cgi-bin/ljdefaults.pl line 56.
43 is:
$SITEROOT ||= "[link|http://www.$DOMAIN:8011|http://www.$DOMAIN:8011]";
56 is:
$COOKIE_DOMAIN ||= ".$DOMAIN";
So, based on that, I'd say the $DOMAIN string isn't getting set somewhere.
Also, Ben is right - there is no ljconfig.pl file there at all. :P Now, I'm poking around in the folder, and find a file in /var/lj/doc named ljconfig.pl.txt, with the following text:
# LiveJournal configuration file. Copy this out of the documentation\n# directory to cgi-bin/ljconfig.pl and edit as necessary. The reason\n# it's not in the cgi-bin directory already is to protect it from\n# getting clobbered when you upgrade to the newest LiveJournal code in\n# the future.\n\n# This should be the only file you need to change to get the\n# LiveJournal code to run on your site. If not, it's considered a bug\n# and you should report it.
:P