Why God Did Not Kill Satan in Job 1
The question assumes the passage explains God's hidden reasons for sparing Satan. Job 1:6–12 does something different: it shows Satan standing among the assembled sons, answering Yahweh's question, and receiving a boundary he cannot cross.
The God of This World: 2 Corinthians 4:3–4
Scripture does describe a spiritual power at work in the present world order, and 2 Corinthians 4:3–4 shows what it does: it darkens minds so the gospel is not seen. The passage claims a specific work of blinding, not unlimited ownership of the earth.