Thosha Thanks, Thosha. My problem solved itself. the meeting with Anna and Sarai seems to have taken place in Chapter 1 during the first visit to Stineford. It's certainly possible, and I just did it, to get the best result for Sarai's Quest by simply following your walkthrough.
The fight with the Unknown God is indeed a bitch, but just follow your tactics and it works. Only problem I had was Aka kept getting knocked flat, so you need a bit of luck in Aka landing a disabling attack at the very beginning OR Aka surviving at least one of the Unknown God's massive magic barrages. Robin having a Supreme Staff AND the Crusader's Amulet 2 (as modified and upgraded in Kaant) AND Otherworldy Robes helps enormously as with all that Robin can ride through all the blasts from UG before she guns it down. Simon just repeatedly heals everyone through the fight except 1st round.