Dear Richard,
openacs tries to call "psql -U <username> ..."
Did you configure the file "/aolserver/openacs/etc/config.tcl" and insert there the proper username and password for openacs?
You can try to start manually the command "psql -U <usernanm>..." from the same command promt window you use to launch openacs. Please check which error messages you're getting.
About the error.log your remak is correct. At the moment it is only available inside the shell buffer.