Raphael is Link's best friend. He appears in his memories. He is the purple-haired guy killed by Thaneris in the ambush in the desert.
Indeed, Kentor was killed by Athel in the battle at the castle front. It's mentioned in the introduction of the game. The Hyrule Army lose because of Thaneris' intervention.
You must transfer all "Save" files to the "Data" folder of the updated version of the game. As a precaution, back up your original game files before making any moves.