[marcmac]

+ sudo /opt/zimbra/openldap/libexec/slapd -l LOCAL0 -4 -u zimbra -h 'ldaps:// ldap://:389/' -f /opt/zimbra/conf/slapd.conf

ldd looks good. Try:

su - root
/opt/zimbra/openldap/libexec/slapd -l LOCAL0 -4 -u zimbra -h 'ldaps:// ldap://:389/' -f /opt/zimbra/conf/slapd.conf

I think there's a -d or -D option that will enable debugging for slapd. Could this be a cert problem? Did you have to remove the ldaps and hack the slapd.conf when you last installed?