CA Privileged Access Manager (PAM) r3.x
CA Threat Analytics for PAM (TAP)
#1. The understanding is correct.
#2 and #3. TAP does not have the clustering feature.
#4. Yes, the usage is so.
#5. Although the PAM structure does not depend on, TAP is integrated with the primary only. The secondary site is not important point for the business, TAP will not be used with the secondary site, but do use the primary site only.