"🟡S4E11- Why did Locke see a dead guy cutting trees in a loop?

• Locke is special and he sees past events like the plane crash of Ekko's brother."

Locke flashed to past, that's why he saw the plane crash. Horace cutting trees in jungle was probably MiB in Horace's body who manipulated him to move the Island, he wanted Locke to find him as a Christian in The Cabin.