With this new chapter format, I'm a little confused about how to ideally save the game. I've read the final chapter will use your character stuff from previous chapters. So...

Should I be saving each chapter on a seperate save slot, or keep overriding the original as I start new chapters?

From what I hear, you should be using different slots because the final chapter needs to read the data for each individual chapter. I'm not 100% sure on this though.

shameless bump

Each storyline should have its own slot. I don't use the word "chapter" because the first and last storylines are three chapters each, but still each only take up one slot. In the end, you should have nine saves:

Base Game (Prologue, Ceodore, Kain)
Rydia
Yang
Palom
Edge
Porom
Edward
The Lunarians
Endgame (Semifinal, Final-1, Final-2)