[Dovecot] LDA without lookup as non-root?

[E.B.]

Hello,

I'm having some problems getting LDA to work without 
userdb lookups and have a few related questions. This system has all 
users in MySQL, each user with unique UID/GID, no local users at all.  
Installation is from apt-get.


1) If LDA is invoked without 
lookups, is it correct to assume that the "service auth" and "service 
auth-worker" can be completely removed from dovecot master 
configuration? (I have tried commenting them out and logging into IMAP, 
which seems to work, not sure if anyone else needs the auth service)


2)
 If LDA is invoked without lookups, will I be unable to use Dovecot 
quota plugin? Does it need to have a user lookup to get quota info? 
(haven't added quota support, need to take this one step at a time)

3) The interesting part -- I am invoking LDA from Maildrop. See:
http://thread.gmane.org/gmane.mail.imap.dovecot/65473
So
 when invoked, Maildrop has already dropped to the destination UID/GID 
and the needed paths are available in the environment.  However, using 
as many permutations of calling LDA as I can think of (based on     http://wiki2.dovecot.org/LDA ), I always get this:

(command line usage error. Command output: lda: Fatal: Couldn't lookup our username (uid=2500) )

The
 UID is correct for the target user. If I add "-d $LOGNAME" to my LDA 
callout, I get permission denied on the userdb lookup, which I guess is 
another issue to work out if I want to go with lookups. But right now I 
am trying not to. Why does LDA seem to try for a lookup even when I 
follow the wiki instructions how to call it without a lookup?

3.5)
 Related question, my users have separate homedir and maildir, both 
paths are looked up by Maildrop. I think I need to call LDA with 
"HOME=$DEFAULT dovecot-lda -f $FROM". Is this correct?