RE: [exim] Help with "Return-Path" modification for Exim 4.4…

If Exim is running under exim user, which of these settings should be removed so I can re-activate trusted_users?
I have read somewhere that root & exim are already trusted implicitly, so leaving trusted_users commented would still work.

Am I creating a security risk by leaving any of these On / Off?

no_local_from_check
untrusted_set_sender = *
never_users = root

# trusted_users = exim:root


PS: 99% of all email from this domain comes from exim user, no other user (except my account occasionally) sends emails from this domain. It's strictly for the email list.