Jedoch keine /etc/pam.d/vsftpd-lc vorhanden. Sollte die da sein?
Ja. 
LiveConfig legt die automatisch an, wenn die Verwaltung des vsftpd über Serververwaltung -> FTP aktiviert wird.
Code
#%PAM-1.0
# _ _ ___ __ _ (R)
# | | (_)_ _____ / __|___ _ _ / _(_)__ _
# | |__| \ V / -_) (__/ _ \ ' \| _| / _` |
# |____|_|\_/\___|\___\___/_||_|_| |_\__, |
# |___/
# Copyright (c) 2009-2016 Keppler IT GmbH.
# ----------------------------------------------------------------------------
# PAM configuration for vsftpd with virtual users
# Maintained by LiveConfig
# Virtual account is sufficient, try local account as fallback:
auth required pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed
auth sufficient pam_userdb.so db=/etc/vsftpd/passwd crypt=crypt
auth required pam_unix.so
# Local account is sufficient, permit any (virtual) account as fallback:
account sufficient pam_unix.so
account required pam_permit.so
# <EOF>-----------------------------------------------------------------------
