1. Locke is the castaway who is manipulated by the island to the greatest extent (e.g. he was given the ability to walk and sees everything as having a faith-based purpose). I use the term “island” to refer to whatever or whoever is “behind the curtain” and pulling the strings on the show.

2. He told Jack that Boone was a sacrifice that the island required, a sacrifice that set them on the path that took them to the hatch.

3. Boone is very similar to the word “boon”.

Main Entry: boon
Pronunciation: ‘bün
Function: noun
Etymology: Middle English, from Old Norse bOn petition; akin to Old English bEn prayer, bannan to summon — more at BAN
1 : BENEFIT, FAVOR; especially : one that is given in answer to a request
2 : a timely benefit : BLESSING

Like Locke said, the island needed a sacrifice. Locke was manipulated, given a vision of the Nigerian plane, and then sidelined with bum legs (what a “coincidence”) so that he would not be put at risk in investigating the plane. The island wanted the plane found, Locke wanted in the hatch. Requests were made.

One last thing: Why did the Island want Boone you ask? Maybe Boone was the first charcter to be redeemed. He’d freed himself of his jealous tie to Shannon (felt “relieved” to have thought she was dead) and he’d confessed his sins regarding Theresa going up and down the stairs. Both of these things were achieved with Locke’s help. Maybe Boone had to die because the island was done with him and his issues were resolved.

(Similarly, I think Shannon might have died because Walt was appearing to her. The island wasn’t into that…)