I'll answer the second one - the new PG RPMs are, I assume, the PG 7.1 RPMs. If you've got an existing PG 7.0 installation you need to:
- PG_DUMP your existing database.
- Stop the postmaster
- move your data directory to a safe place as a backup (/usr/local/pgsql/data in a standard installation build from source).
- make and install PG 7.1
- initdb
- start postmaster
- createuser your_user
- createdb your_db;createlnag plpgsql your_db; createlang pltcl your_db
- psql your_db -f your_dmp.dmp
- vacuum analyze your_db
- rebuild the Postgres driver (get latest source from sourceforge)
- restart openacs.
