Shevuot 8: Atonement or Suspended Punishment on Yom Kippur?

Does the goat-offering atone for 3 different kinds of impurities? The verse indicates it won't atone for all kinds of impurities, only some of them. But what kind of impurities does it atone for? Perhaps for an idolater - but it's too egregious of a transgression. Perhaps for a woman after childbirth -- but what is her sin for which she brings a sin-offering? Perhaps she has (falsely) sworn off relations with her husband in the throes of labor (but it's a machloket). So the Gemara comes around to talking again about the impurity that is brought into the Temple or with regard to its sanctified foods -- inadvertently, to be sure. But how does this atonement relate to the atonement provided by the day of Yom Kippur? What if a person doesn't have time to bring the atoning offering before Yom Kippur?