Hi look at the below points
1. User wise login stats.
Once user is logged in you can get the relevant information from Governance dashboard
2. Users for whom the document has beenbut user never logged in.
Hard to find this information, No direct way I suggest you to go through QVPR document
3. User Status( Active - Disabled )
It will not be carried at Qlik level.
4. Which Tab and object in the dashboard is being mostly used (user-wise)
Look at governance dashboard for the same
5. Errors that occurred while dashboard was being used by users.
Governance Dashboard, QVPR, System monitoring.