Using vinegar to set unstable dyes isn't that uncommon--and I think it tends to be dark colors just cuz that's when you notice it--but as dyes have become more stable, it seems like it's less and less necessary. That said, I do still wash my bright red towels only with dark colors, in case they run.
As for the shedding issue, I can't say why, but I did give away 4 lovely new bath sheets for exactly this reason--they shed little pills all over me when I tried to dry myself, and they felt...greasy somehow. Blick.
"Don't put all your eggs in one basket.
Use an egg carton like everyone else and stop being such a poser." - The Little Book of Wrong Shui