1)
What is the significance of murder and idolatry?
1.
Malbim: For these, the land expels its residents ? "Ki ha'Dam Hu Yachanif Es ha'Aretz" (Bamidbar 35:33), and it says at the end of the Arayos "v'Lo Saki ha'Aretz Eschem b'Tama'achem Osah" (Vayikra 18:28).