These are the questions asked during Mobile Device Management Training
In the case of Android devices, the user can enable "Prevent users from removing ME MDM app from the device" option under "Enrollment Settings".
In the case of supervised iOS devices, Under "Profiles", Disable the restriction "Uninstalling Apps". This will prevent the users from deleting apps from the devices.
The licenses purchased using Managed Distribution, from VPP can be reused. If an app is distributed to a device, a license will be used. Once the app is removed from the device, the license will be added back to your account and can be used to distribute an app to another device.
Mobile Device Manager Plus allows admins to send out various app configurations to devices along with the apps. This is supported for both iOSand Android apps. These configurations can be applied only if they are provisioned by the respective app developer.
Only if you are using Exchange Server 2010, enable Basic Authentication to configure Conditional Exchange Access. Follow the steps given here to configure it.