Licenses and AD Import Questions

We've recently ran over our license count and i am trying to clean up the stale entries.  I have already set the manager to delete clients that have not connected for 14 days.  I have a few questions.

How does SEPm count for laptops that are offline for over a month?

When AD syncs, all the old computer objects are also imported.  Do those stale computer objects count as a license?

Is there a way to run a report on all the machines that actually take up 1 license?

Thank you