Try "magctl appstack status " or even in GUI under Sytem settings> system 360 page , you should see the list of services which are running in each Node.But yes as a Admin you can't choose if NCP should on one and NDP to be on another , Maglev and kub...
Yes you can configure email notifications for Assurance events , please have a look at below link.https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center-platform/1-3-1-0/user_guide/b_dnac_platform...