As the others have said they're definitely for a rack, and if you don't have corresponding eyes on the dropouts it might be because the maker prepares all their seatstays for the various versions of their frames, but on yours elected not to include fender eye dropouts. (Which IMO is a major sin committed by the bike factories today, given the tiny weight consequences vs. the user options they create).

The seatstay mounts provide more rigidity to racks, and you can always use P-clips at the lower end.

As to the brake cable. I think it's a bit long, though I should add that I'm a fanatic about fair lead in cable runs. Every curve in housing causes friction, so you want to avoid reverse curves like the up curve coming from the frame fulcrum. I know it's hard on a frame as short as yours, but I think there might be room to bring the height of the loop lower for a better run. OTOH, if it works it isn't worth changing, but might be worth trying next time.