OnePlace Solutions desktop uses a Subscription Id. On a paid Subscription, the subscription id will be automatically available for all users in your environment.

It is possible to add a single connection to OnePlaceMail or OnePlaceDocs. To add a SharePoint connection to multiple users, please use the Configuration Profile

Yes, OnePlaceMail and OnePlace Docs can be deployed through group policy, SCCM, or InTune - and other deployment tools. Click here for further information.