pg_restore ERROR

After running pg_dumpall on my database cluster like this:

$PGBIN/pg_dumpall -c -U ipscdb | gzip > /var/db/pgsql_bkp/pg_dump_file.gz

I subsequently delete the PGDATA directory for the backed up database and
initialize a new database. Next I attempt to run the restore using
initialized database like this:

cat /var/db/pgsql_bkp/pg_dump_file.gz | gunzip | $PGBIN/psql postgres >
/dev/null

This results in a couple of error messages:

ERROR: current user cannot be dropped

ERROR: role "ipscdb" already exists

Since I ran initdb to initialize my database after the pg_dumpall as
"ipscdb" user, and subsequently am running the restore as "ipscdb" user, it
does make sense that I see these errors. The first one is caused by the -c
switch on pg_dumpall which generates the script to drop all database objects
before restore is done. The second is a consequence of the first one -
script is attempting to create a role, which already exists.

My questions are:

1) What would be the right way to do this? (other than pg_restore
with the create option)

2) Does the restore go forward despite the two errors shown above -
meaning that I can pretty much ignore these errors?

Thanks in advance,

~george