Pesachim 77: The Holy Frontplate and Its Influence

5 different offerings from the mishnah on daf 76 that can be offered by those who are impure, though it's not eaten by those who are impure. As compared to other sacrifices, which cannot be eaten or offered in impurity. And as compared to the Korban Pesach. Plus, why identify this list as specifically "5"? What is excluded and why? Also, is the principle that allows for the korban one of "d'chuya" (pushing off) or "hutra" (actually permitted)? And what does the "tzitz" - from the garments of the kohen gadol that permits it, perhaps in the metaphysics of the mitzvot here. Also, the dispute between R. Eliezer and R. Yehoshua, to what extent does the tzitz affect the acceptance of the korban?