No, Session Key and Persistent Key/Session Ticket Key are NOT same.
Session Keys- used to encrypt traffic to/from the PS
Session Ticket Keys/Persistent Key - used by PS to encrypt session and identity specs
Session Keys are NOT stored in the policy store. They are auto generated using some seed.
While operating in FCC Compat Mode, it uses RC4-128 bit cipher (Session Keys) to encrypt traffic between Policy Server and Web Agent.
While operating in FCC Migration Mode or FIPs Only Mode, it uses AES-128 bit cipher to encrypt traffic between Policy Server and Web Agent.