Interesting to see this Carabela "Carrera Sport" model has a Falck tubing decal (plus the Sun Tour DOs) since most Carreras (either Windsor or Carabela, when you find those) were said to be nothing better than gas pipe.
Falck would be a bargain tubeset but still a step up.

Is this a combo cable stop, cable guide, spoke catcher?
Exactly so but to hold spare spokes you need something at the other end into which your threaded ends w/nipples are fixed, at which point your spokes act as "chain slap protection"...win/win/win!