On the incense as a mechanism of atonement. Specifically for lashon hara, evil speech. Which aligns neatly, in terms of the scent and spread of it atoning for the spread of lashon hara. Plus, it's more comfortable for modern sensibilities that have a hard time with animal sacrifice. Also, on separating between the antechamber and the altar, the blood of korbanot vs. that of idolatry. But is this d'Oraita or deRabbanan? What confusion is this, where people can wander into the prohibited area, between the main hall and the altar... Could you really wander into the wrong place? Maybe that's the challenge itself. Plus, the silver and gold of the pan used by the kohen gadol for the coals - where there's only gold on Yom Kippur, and the silver of the rest of the year is supposed to ease the burden of covering the cost by the people.