Ah, I think I misunderstood your original post. We're on the same page now.
The only problem with your theory, which is a good one, is that Painter's people have used telescopes to see their neighboring planet and can tell it's inhabited. If they were looking at Taldain, the light from the star would totally wash out the visibility of Taldain (the planet). So I think it's more likely that Painter's "star" is another planet in the same system.