psql asks for password, CREATE USER didn't specify one
A user having a password or not won't affect if you're asked for a password when trying to connect.  That is controlled by the pg_hba.conf file.

If you're being asked for a password that indicates that a password is required.  If you try to connect to an account which doesn't have a password set that will simply fail.  You need to either set a password for the account and use that, use a different type of connection or modify the pg_hba.conf file to use a different authentication method.