: 1. Are AIs supposed to have been the real reclaimers all along, or is that
: just the Warden's interpretation? Seems like 343 GS called humans
: reclaimers in Halo 2 and 3 even without AIs present. e.g. "this
: reclaimer is fragile".

: 2. What the hell did the librarian do to Cortana, and why? was all this part
: of the librarian's plan?

: 3. The cryptum that Blue Team was in looks a lot like the Diadact's egg thing
: from Halo 4. If that was a cryptum, why was he able to fly it around and
: exit it at his leisure?

: 4. Are the Prometheans still human intelligences? Are they the ones from New
: Phoenix (as in Spartan Ops) or from somewhere else?

: 5. Where the hell is Half-Jaw

: 6. Did HTT have anything at all to do with Halo 5? Doesn't seem like it.

1. No, I think Cortana being sent into the Domain was an accident and that she is claiming that title for herself now that she's in control of everything. She's taking the Mantle for her own kind, much like how the Didact refused to give it up from his own species. Humanity is just kinda sitting between the two waiting for our turn with the toy. I think that 343 GS calling the Chief a Reclaimer in The Library and the other number of incidents with Forerunners and their Sentinels referring to humanity as Reclaimers with no AI present proves this. Cortana is just being selfish.

2. I can't actually answer that, but it's possible that the Librarian set the events in motion to get Cortana to the Domain and to setup the galaxy with the Guardians at the end of Halo 5. Maybe to prepare for the return of the Forerunners? Or the Flood?

3. The Didact was unable to leave his Cryptum or manipulate it until the Master Chief released him. It's possible that Blue Team would've been able to do the same after Locke releases them, but it was irrelevant because of the other things happening. Or it could've been a different class of Cryptum. Or Blue Team, once released, didn't know how to drive the damn thing.

4. Watchers/Crawlers are entirely artificial, just the Knights were composed humans. Soldiers could be either, but we don't really get an information on this. It's likely that these Prometheans are older ones who were protecting the Guardians and awoke when Cortana started to activate them. So it's unlikely that they are the composed humans, at least from New Phoenix.

5. YEAH, WHAT THE HELL!? I WANTED HALF JAW BACK! :(

6. It sets up the universe and gives us an idea of the impact the Guardians are having on the human and alien colonies. The Master Chief makes a point of asking Cortana if she realizes how many people she's killed and how she's destroying the colonies. FERO becoming an AI could mean that she also allies with Cortana in the end of the game, for all we know. It's definitely relevant.