Have a look at the following page: https://docs.mendix.com/refguide/monitoring-mendix-runtime
It describes how you can fetch data from the admin port you define when running a mendix app.
No , at least not yet. I know they are opening up the database for Datadog. But there are to my knowledge not yet much info on (you can see some hints in the release notes of the developer portal). You could file a Idear in the Ideas part of the forum.