Well, i could try to argue what "limited" in relation to the flow-walking, but there's no point. Force can give glimpses of possible future and perhaps gives means to influence what will come to pass. And future is always in motion. It seems that we agree that much.
Why do you think that the reasons for Jacen's "downfall" are limited to only those that have been explored in text?
Because, frankly speaking, i see them as sufficient. And, since adding Abeloth into them would undermine their importancy, i'm against doing that. Not that my opinion matters much in the grand scheme of things, of course.
Have you been gifted with a 'Complete Works of Star Wars' from the future?
What would i need it for? )
What information do you have about the franchise that we don't?
What would i need it for? )
IMO, Jacen won't be in focus of "Fate of jedi" anymore, since Lost Tribe of Sith, Abeloth and possibly Mandalorians would have spotlight. Jacen's ghost in the lake seems to be appropriate end for his "involvement" (quoted for J. being dead) in the series. Sure thing, he may be adressed in later books, but i doubt that.
Sorry for off-topic.
It would be fun to have Mandalorians vs. Sith as a full-blown conflict. And, until Daala dies or goes crazy, there shouldn't be any attempts at another purge of Jedi