Is there any standard Data model in SAC which will give the information on all the data models which is being used and their data type and measures and dimension

Now only Named user license is available in SAC. How we can anlysis the usage of these licesnse consumed in SAC instead of standard or custom report?Any Standard data model we can use to create a report?

Currently we have a lot of users using Concurrent license and that will changing to named user licesnses.So how we can do this activity on a mass bunch of users(2000+ users)? Kindly provides a detailed plan.

When SAC pre prod is scheduled for upgrade ? Is there any way to find out the dates?

Which standard Data Model I can use to build SAC story to find out the inactive users(last 3 month)?