ANS to Q1: Calls older than the day specified for the 'Days to retain calls' setting that are still seen and playing back on the ACR replay page are doing so because of the setting of the 'Call details' retention period as well as the Archive retention period. Calls playing back are from the Archive system.
ANS to Q2: To retend call recordings for a long time on the ACR server, there must be sufficient disk space to accomodate that. Without sufficient disk space for the call recordings, the ACR will purge calls based on FIFO principle.