My last RS had a knock sensor code when I bought it. Never came back after the ECU was reset during the clutch install.
AFAIK, the RS ECU doesn't do the blinky light/limp-home mode for excessive knocking... and it's awfully hard to get a more or less stock EJ25 to knock anyway. But, the CEL is not related to the starter problem, unless there's some weird circuit in there that makes no sense to those of us who don't engineer Subarus for a living.
