silly q-n
how can I get an email if status of one or several miners goes down or hash rate significantly changes?
In the first post are links to a few monitors. I setup the CKPool Status for Android and it will notify you through the app. There's also CKPool Monitor, which looks like you can setup email notification. I haven't used that one though.
CK Pool Monitor is good. I use it. It will give you exactly what you're wanting...you can set up alerts per worker based on hash rate, etc.