Found a workaround with external identification....that might be the solution I will use....

But I don't really want to create a user for this and the question
is if this user that have an external identification can be sysdba?

Another question is if I can start an import thru sqlplus?
# sqlplus '/as sysdba'
SQL>

I can mention that the reason that I want to be able to connect without passwords is that I am witing shllescripts that will create
a user, a tablespace, grants and then import data from an export-dump...
I don't want the password as clear text in my scripts...