Part 1:
"They even got an explanation, as far as you can explain their roots and purpose. They were the candidate numbers and corresponded with a degree in the lighthouse that acted as a window to the characters past."
I don't want to argue, but I don't agree with this :D
Walt:
"Pearson Moore argues that the questions surround Walt is simple and that his powers came from The Island."
Grammar? :>
Pilot:
"Lost wasn’t created with a six-year plan. Rarely do you see that with network shows."
I'd say that you rarely see that with any show... no matter whether it's on network TV, HBO or Netflix. People often bring up Babylon 5, but that show isn't representative of anything, especially because there were 5 or 6 years between the conception and the actual production of the show. And even the showrunner of B5 acknowledged that he had to adapt and change things on the fly, because plans don't matter.
"Variety reports that a little over a quarter of the pilots that are produced turn into series."
Even less pilots get even produced after a script had been ordered and written.
"ABC greenlit the pilot from a story treatment (not a script) that was fifteen pages long (Vaz 2004, p. 23).
The final outline is actually 21 pages. Or 22. That depends on the formatting :D
"They even called J.J. Abrams when he was on set asking if they could shoot an alternate ending and make it a standalone movie instead (Vaz 2004, p. 30)."
That line is rather relevant. The network/Disney (after Braun left and the show had no advocate anymore) was pretty much against the show. After they finished the pilot they even suggested that they make 6 more episodes to conclude the show. Any plan whatsoever wouldn't have mattered anymore in that case. Walt would never have been an issue.
"Walt being less present in the show makes perfect sense in the complicated landscape that is mid-2000's television. Planning a show many years in advance from the Pilot is not how the television industry worked at that time"
It doesn't even work like that today.
"This was the day before they handed in the script for the pilot."
This was just the first draft of the script, not even the finale one. Meaning at that point in time Jack was still supposed to be killed off. Things change, ideas evolve. Changes lead to other changes in a chain reaction, which makes creating elaborate plans pointless and counter-productive.