I'm aware than ossec notices when certain files are changed, but this mechanism isn't useful as it gets hidden in the "noise" of other alerts.

What I'd like is an email notification triggered when certan "critical" files are changed. For example, Plesk MU#32 reset smtp_psa and smtps_psa to their defaults, killing off spamdyke. If I hadn't been looking for it, I would not have noticed it.

I'd really like a clear alert when something like that happens.

Same probably goes for qmail_send or whatever it is that gets changes that causes qmail-scanner to stop working.

Basically if any imporant config flle that isn't in the self-healing list changes, I'd like to know about it.

Of course I can't think of anything else other than httpd.conf and php.ini (which I've never seen changed by Plesk, thankfully, so maybe not good candidates), but doubtless there are some.

The ftp files would be nice too, maybe the psa.conf file too

Have you tried out the "Watch" function in the File Integrity manager? You can set a watch on a file or directory, the level to alert at (say 13 in your example) and a custom email address if youd like. My original idea for this was to let you use it for domain level owners to get HIDS alerts when their domains change. You could certainly use it for this too:

In ASL Web select:
-> ASL
-> File Integrity
-> Options
-> Directories
-> Add new rule:
-> Select: notify
Path: /path/to/file/or/directory
Level: XX (13 for example)
Email to: <your@email.address>
-> Click update

Cool! I wasn't aware of this feature.

ASL is probably to application I least like to experiment with, so if I don't absolutely need to do something I don't touch it

Also if you select the "Report Changes" option it will send you the diffs of the changes made to an ASCII file