I've downloaded ACSv3.2.4 and found that not all sql are loaded
during installation (like the webmail.sql). Is there any
documentation (besides version-history.html) indicating the modules
being ported into OpenACS architecture?
Most modules have been ported. A few are not but they are minor modules with exception of webmail (which I think has been ported by Dan). You need ns_java (a Java module for AOLserver) to use webmail though. It's available at nsjava.sourceforge.net.
Make sure you have the right path for your PostgreSQL libraries in the postgres.sql. See the OpenACS documentation for more details. Check the permissions to make sure all files are readable by the user that's calling psql.