Allocating Document CALs (i.e. putting them aside in a pool for a specific document) is not the same as assigning them. In contrast to Named CALs, Document CALs are first allocated (reserved for a specific document = pool), and only then will you assign them.
Does that explain your situation?
Indeed, you can choose to automatically assign Document CALs per Document by first allocating a pool of CALs and then enabling the option "Allow dynamic CAL assignment" in QMC. As long as there are free CALs available from the pool, every visitor to this document in the AccessPoint will get a CAL.
Note that there is no mechanism in QMC to release unused CALs back to the pool. This is a licensing restriction as well.
Yes, go to documents tab --> user document --> Select your application--> Go to Document Cal tab
In the section assigned users you will see the list of users to whoom a cal is allocated.
Note: the time you see there will be UTC time. add +- hours depending on your timezone to get exact time.
Hope it helps
If on the other hand you want to find out on what date a CAL was first assigned to a specific user, AFAIK there is no easy way to obtain that informaiton in the QMC.
However you can find something like that in the Events log of the QlikView Server. See How to get the date on which a document CAL/user was assigned to a document