I think I watched that vid before (though maybe time for a rewatch) - the deeper Kreia lore is fucking awesome - especially the more you learn about her teaching Revan, etc.

It's basically all of that, and an excellent breakdown of her philosophy in regards to the force itself.

Which completely went over my head when I played KOTOR 2, as a kid.

To be fair, a lot of the content focusing on her force philosophy was cut from the original game.

I assume you've played the Sith Lords Content Restoration mod? It's the one that restores all (or almost all) of the planned cut content - it even includes a new level on the surface of Telos (There's a bunker on the planet that you otherwise can't go into, but with this mod it lets you into the HK Factory - it's part of a huge HK quest line that was restored).

There's also lots of little dialogue scenes and choices restored too, and the ending is more fleshed out.

It certainly isn't a replacement for the devs actually finishing the game (they pushed it out rushed because of deadlines forced on them from the publisher), but it's as close as we're ever going to get without a mod that starts to introduce fan-made content to make up what we don't know.

I have not, I need to do so.

Let me know when you've had a chance to play some of the cut content - I always enjoy discussing anything KOTOR.